23 Ways to Nudge: A Review of Technology-Mediated Nudging in Human-Computer Interaction
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paper_title: Use and Adoption Challenges of Wearable Activity Trackers

paper_content:

Wearable activity trackers are becoming widely adopted, yet challenges continue to exist in effective longterm use and adoption. Existing research focuses mostly on the use and adoption challenges associated with technicalor device-related issues and respective workaround strategies. Little is known about how personal preferences and other individual characteristics affect use and adoption of wearable activity trackers. In this paper, we present a six-week user study of 26 users using physical activity trackers embedded in clip-on and smart watch physical devices. We describe novel implications of the usage patterns, including the need to help people be mindful of their physical activity trackers, to understand and further articulate gender differences in use and adoption of wearable devices, to incorporate big data analytics in informing and coaching people’s practices, and to reframe data inaccuracy as a byproduct of mismanagement of expectations of the device’s capabilities and its expected usage.
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paper_title: Reconsidering the device in the drawer: lapses as a design opportunity in personal informatics

paper_content:

People stop using personal tracking tools over time, referred to as the lapsing stage of their tool use. We explore how designs can support people when they lapse in tracking, considering how to design data representations for a person who lapses in Fitbit use. Through a survey of 141 people who had lapsed in using Fitbit, we identified three use patterns and four perspectives on tracking. Participants then viewed seven visual representations of their Fitbit data and seven approaches to framing this data. Participant Fitbit use and perspective on tracking influenced their preference, which we surface in a series of contrasts. Specifically, our findings guide selecting appropriate aggregations from Fitbit use (e.g., aggregate more when someone has less data), choosing an appropriate framing technique from tracking perspective (e.g., ensure framing aligns with how the person feels about tracking), and creating appropriate social comparisons (e.g., portray the person positively compared to peers). We conclude by discussing how these contrasts suggest new designs and opportunities in other tracking domains.
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paper_title: Losing Control: How and Why People Fail at Self-Regulation

paper_content:

Basic Issues: Introduction: Self-Regulation Failure in Social and Theoretical Context. General Patterns and Mechanisms of Self-Regulation Failure. Controlling Thoughts, Feelings, and Actions: Task Performance and Self-Regulation Failure: Blowing It. Self-Management: Taking Care of Yourself. Thoughts Out of Control. Failure to Control Emotions and Moods. Controlling Impulses and Appetities: Impulses and Appetites. Alcohol Consumption and Abuse. Eating Too Much. Smoking. A Sampler of Other Behavioral Control Problems: Gambling, Shopping, and Aggression. Conclusion: Self Regulation: Propects, Problems, and Promises. References. Subject Index.
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paper_title: How do we engage with activity trackers?: a longitudinal study of Habito

paper_content:

We report on a 10-month in-the-wild study of the adoption, engagement and discontinuation of an activity tracker called Habito, by a sample of 256 users who installed the tracker on their own volition. We found 'readiness' to behavior change to be a strong predictor of adoption (which ranged from 56% to 20%). Among adopters, only a third updated their daily goal, which in turn impacted their physical activity levels. The use of the tracker was dominated by glances -- brief, 5-sec sessions where users called the app to check their current activity levels with no further interaction, while users displayed true lack of interest in historical data. Textual feedback proved highly effective in fueling further engagement with the tracker as well as inducing physical activity. We propose three directions for design: designing for different levels of 'readiness', designing for multilayered and playful goal setting, and designing for sustained engagement.
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paper_title: Mining behavioral economics to design persuasive technology for healthy choices

paper_content:

Influence through information and feedback has been one of the main approaches of persuasive technology. We propose another approach based on behavioral economics research on decision-making. This approach involves designing the presentation and timing of choices to encourage people to make self-beneficial decisions. We applied three behavioral economics persuasion techniques - the default option strategy, the planning strategy, and the asymmetric choice strategy - to promote healthy snacking in the workplace. We tested the strategies in three experimental case studies using a human snack deliverer, a robot, and a snack ordering website. The default and the planning strategies were effective, but they worked differently depending on whether the participants had healthy dietary lifestyles or not. We discuss designs for persuasive technologies that apply behavioral economics.
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paper_title: Why we use and abandon smart devices

paper_content:

Smart devices are becoming increasingly commercially available. However, uptake of these devices has been slow and abandonment swift, which indicates that smart devices may not currently meet the needs of users. To advance an understanding of the ways users benefit from, are challenged by, and abandon smart devices, we asked a group of users to purchase smart sensing devices to advance themselves towards a personal, self-defined goal. We found that participants abandoned devices because they did not fit with the their conceptions of themselves, the data collected by devices were perceived to not be useful, and device maintenance became unmanageable. Participants used devices because they had developed routines and because devices were useful, satisfied curiosity, and held hope for potential benefit to them. We propose ways to reduce barriers, motivate use, and argue for envisioning an additional function of these devices for short-term interventions, in addition to standard long-term use.
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paper_title: Fostering Engagement with Personal Informatics Systems

paper_content:

Personal informatics systems are becoming increasingly prevalent as their price, form, and ease of use improves. Though these systems offer great potential value to users, many systems are hampered by issues that limit their ability to foster engagement, and people often abandon use of these systems without garnering meaningful outcomes. While continued use of these systems is not necessary for all people, there is an opportunity to better support people working towards achievement-based goals. In this paper, we draw from the literature and our own prior work to identify a number of problems that hinder engagement with achievement-based personal informatics systems -- problems related to inadequate support for goal-setting, misalignment of user and system goals, and the burden of system maintenance. We then propose seven strategies for the design community to explore for mitigating these problems and discuss how these strategies could be used to foster engagement with PI systems.
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paper_title: Mindless computing: designing technologies to subtly influence behavior

paper_content:

Persuasive technologies aim to influence user's behaviors. In order to be effective, many of the persuasive technologies developed so far relies on user's motivation and ability, which is highly variable and often the reason behind the failure of such technology. In this paper, we present the concept of Mindless Computing, which is a new approach to persuasive technology design. Mindless Computing leverages theories and concepts from psychology and behavioral economics into the design of technologies for behavior change. We show through a systematic review that most of the current persuasive technologies do not utilize the fast and automatic mental processes for behavioral change and there is an opportunity for persuasive technology designers to develop systems that are less reliant on user's motivation and ability. We describe two examples of mindless technologies and present pilot studies with encouraging results. Finally, we discuss design guidelines and considerations for developing this type of persuasive technology.
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paper_title: The automated will: Nonconscious activation and pursuit of behavioral goals

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It is proposed that goals can be activated outside of awareness and then operate nonconsciously to guide self-regulation effectively (J. A. Bargh, 1990). Five experiments are reported in which the goal either to perform well or to cooperate was activated, without the awareness of participants, through a priming manipulation. In Experiment 1 priming of the goal to perform well caused participants to perform comparatively better on an intellectual task. In Experiment 2 priming of the goal to cooperate caused participants to replenish a commonly held resource more readily. Experiment 3 used a dissociation paradigm to rule out perceptual-construal alternative explanations. Experiments 4 and 5 demonstrated that action guided by nonconsciously activated goals manifests two classic content-free features of the pursuit of consciously held goals. Nonconsciously activated goals effectively guide action, enabling adaptation to ongoing situational demands.
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paper_title: Anomalies: The endowment effect, loss aversion, and status quo bias

paper_content:

most (all?) behavior can be explained by assuming that agents have stable, well-defined preferences and make rational choices consistent with those preferences in markets that (eventually) clear. An empirical result qualifies as an anomaly if it is difficult to "rationalize," or if implausible assumptions are necessary to explain it within the paradigm. This column presents a series of such anomalies. Readers are invited to suggest topics for future columns by
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paper_title: Heuristics made easy: An effort-reduction framework

paper_content:

In this article, the authors propose a new framework for understanding and studying heuristics. The authors posit that heuristics primarily serve the purpose of reducing the effort associated with a task. As such, the authors propose that heuristics can be classified according to a small set of effort-reduction principles. The authors use this framework to build upon current models of heuristics, examine existing heuristics in terms of effort-reduction, and outline how current research methods can be used to extend this effort-reduction framework. This framework reduces the redundancy in the field and helps to explicate the domain-general principles underlying heuristics. The word "heuristic" has lost its meaning. That is to say, researchers have used the word so widely as to render it a vague, catch-all term for explaining decision processes. Oftentimes the word is cursorily defined as a "rule of thumb" or a "mental shortcut" for solving problems, but what does that mean? Because the term "heuristic" is vague enough to describe anything, it has been used to describe nearly everything. It seems that we have reached the point where the literature has become flooded with so many heuristics as to make the term arbitrary. This raises the question: What is a heuristic? Simon (1990), the father of heuris- tics research in judgment and decision making, argued that heu- ristics are "methods for arriving at satisfactory solutions with modest amounts of computation," suggesting that people seek to reduce the effort associated with decision processes (p. 11). To further define the nature of heuristics, we propose a framework that focuses on the ways that heuristics reduce the effort associated with tasks. Using this framework allows us to organize previous research on judgment and decision making in a cohesive manner and to provide a new focus for future research. Furthermore, this framework extends current heuristic theories and can be applied to resolve some of the confusions and problems within the literature on heuristic processing. Before outlining the properties of heuristics, we should remem- ber the purpose heuristics serve in the first place. The term "heu- ristic" was brought to wide attention in psychology when A. Newell and Simon (1972) used the word to describe simple pro- cesses that replace complex algorithms. In judgment and decision making, the weighted additive rule is one complex algorithm for arriving at optimal decisions and accurate judgments (Payne, Bett- man, & Johnson, 1993). According to the weighted additive rule, decision makers con- sider all of the available alternatives and cues for each alternative. Decision makers must weight each cue according to objective or subjective impressions of how it contributes to an alternative's overall value. Once decision makers arrive at a weighting principle and assign weights to each cue, they must then calculate the value for each alternative. Each cue's value is multiplied by its corre- sponding weight, and these products are summed to yield the overall value for an alternative. Ultimately, using the weighted additive rule consistently requires people to expend effort on five tasks:
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paper_title: Using personal examples to improve risk communication for security & privacy decisions

paper_content:

IT security systems often attempt to support users in taking a decision by communicating associated risks. However, a lack of efficacy as well as problems with habituation in such systems are well known issues. In this paper, we propose to leverage the rich set of personal data available on smartphones to communicate risks using personalized examples. Examples of private information that may be at risk can draw the users' attention to relevant information for a decision and also improve their response. We present two experiments that validate this approach in the context of Android app permissions. Private information that becomes accessible given certain permissions is displayed when a user wants to install an app, demonstrating the consequences this installation might have. We find that participants made more privacy-conscious choices when deciding which apps to install. Additionally, our results show that our approach causes a negative affect in participants, which makes them pay more attention.
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paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
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paper_title: Mining behavioral economics to design persuasive technology for healthy choices

paper_content:

Influence through information and feedback has been one of the main approaches of persuasive technology. We propose another approach based on behavioral economics research on decision-making. This approach involves designing the presentation and timing of choices to encourage people to make self-beneficial decisions. We applied three behavioral economics persuasion techniques - the default option strategy, the planning strategy, and the asymmetric choice strategy - to promote healthy snacking in the workplace. We tested the strategies in three experimental case studies using a human snack deliverer, a robot, and a snack ordering website. The default and the planning strategies were effective, but they worked differently depending on whether the participants had healthy dietary lifestyles or not. We discuss designs for persuasive technologies that apply behavioral economics.
---
paper_title: Mindless computing: designing technologies to subtly influence behavior

paper_content:

Persuasive technologies aim to influence user's behaviors. In order to be effective, many of the persuasive technologies developed so far relies on user's motivation and ability, which is highly variable and often the reason behind the failure of such technology. In this paper, we present the concept of Mindless Computing, which is a new approach to persuasive technology design. Mindless Computing leverages theories and concepts from psychology and behavioral economics into the design of technologies for behavior change. We show through a systematic review that most of the current persuasive technologies do not utilize the fast and automatic mental processes for behavioral change and there is an opportunity for persuasive technology designers to develop systems that are less reliant on user's motivation and ability. We describe two examples of mindless technologies and present pilot studies with encouraging results. Finally, we discuss design guidelines and considerations for developing this type of persuasive technology.
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paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
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paper_title: Guidelines for snowballing in systematic literature studies and a replication in software engineering

paper_content:

Background: Systematic literature studies have become common in software engineering, and hence it is important to understand how to conduct them efficiently and reliably. Objective: This paper presents guidelines for conducting literature reviews using a snowballing approach, and they are illustrated and evaluated by replicating a published systematic literature review. Method: The guidelines are based on the experience from conducting several systematic literature reviews and experimenting with different approaches. Results: The guidelines for using snowballing as a way to search for relevant literature was successfully applied to a systematic literature review. Conclusions: It is concluded that using snowballing, as a first search strategy, may very well be a good alternative to the use of database searches.
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paper_title: Leading people to longer queries

paper_content:

Although longer queries can produce better results for information seeking tasks, people tend to type short queries. We created an interface designed to encourage people to type longer queries, and evaluated it in two Mechanical Turk experiments. Results suggest that our interface manipulation may be effective for eliciting longer queries.
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paper_title: Anomalies: The endowment effect, loss aversion, and status quo bias

paper_content:

most (all?) behavior can be explained by assuming that agents have stable, well-defined preferences and make rational choices consistent with those preferences in markets that (eventually) clear. An empirical result qualifies as an anomaly if it is difficult to "rationalize," or if implausible assumptions are necessary to explain it within the paradigm. This column presents a series of such anomalies. Readers are invited to suggest topics for future columns by
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paper_title: Status-Quo and Omission Biases

paper_content:

Bias toward the status quo, found in choice and in emotional reactions to adverse outcomes, has been confounded with bias toward omission. We unconfounded these effects with scenarios in which change occurs unless action is taken. Subjects reacted more strongly to adverse outcomes caused by action, whether the status quo was maintained or not, and subjects preferred inaction over action even when inaction was associated with change. No status-quo bias was found in a matching task, which did not require action. The observed status-quo bias is at least partly caused by a bias toward omissions.
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paper_title: Impersonal Default Rules vs. Active Choices vs. Personalized Default Rules: A Triptych

paper_content:

Impersonal default rules, chosen by private or public institutions, establish settings and starting points for countless goods and activities -- cell phones, rental car agreements, computers, savings plans, health insurance, websites, privacy, and much more. Some of these rules do a great deal of good, but others might be poorly chosen, perhaps because the choice architects who select them are insufficiently informed, perhaps because they are self-interested, perhaps because one size does not fit all. The existence of heterogeneity argues against impersonal default rules. The obvious alternative to impersonal default rules, of particular interest when individual situations are diverse, is active choosing, by which people are asked or required to make decisions on their own. The choice between impersonal default rules and active choosing depends largely on the costs of decisions and the costs of errors. If active choosing were required in all contexts, people would quickly be overwhelmed; default rules save a great deal of time, making it possible to make other choices and in that sense promoting autonomy. Especially in complex and unfamiliar areas, impersonal default rules have significant advantages. But where people prefer to choose, and where learning is both feasible and important, active choosing may be best, especially if people’s situations are relevantly dissimilar. At the same time, it is increasingly possible for private and public institutions to produce highly personalized default rules, which reduce the problems with one-size-fits-all defaults. In principle, personalized default rules could be designed for every individual in the relevant population. Collection of the information that would allow accurate personalization might be burdensome and expensive, and might also raise serious questions about privacy. But at least when choice architects can be trusted, personalized default rules offer most (not all) of the advantages of active choosing without the disadvantages.
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paper_title: Can We Nudge Users Toward Better Password Management?: An Initial Study

paper_content:

Nudge theory has been widely used in government and health interventions for the subtlety with which it positively influences choices. But, can this gentle nudge influence users to exhibit secure online account behaviors? And further, which of the nudge types is most effective? We conducted a between-subjects experiment with five conditions, plus a control, in which participants (n = 263) experienced different types of nudges (incentives, norms, default, salience, ego) before indicating their comfort levels with an auto-generated password and intentions to create a new password. Results show the salience nudge most effectively reduced one's comfort level with keeping the auto-generated password. These preliminary findings imply nudges using multiple psychological effects could serve as important design cues, thereby making intended behaviors easy to perform.
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paper_title: Changing the default to promote influenza vaccination among health care workers

paper_content:

BACKGROUND ::: The prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure. ::: ::: ::: METHODS ::: HCWs were randomly assigned to one of two conditions. In the opt-out condition (N=61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N=61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated. ::: ::: ::: RESULTS ::: The findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated. ::: ::: ::: CONCLUSION ::: To change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.
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paper_title: Towards Making Random Passwords Memorable: Leveraging Users' Cognitive Ability Through Multiple Cues

paper_content:

Given the choice, users produce passwords reflecting common strategies and patterns that ease recall but offer uncertain and often weak security. System-assigned passwords provide measurable security but suffer from poor memorability. To address this usability-security tension, we argue that systems should assign random passwords but also help with memorization and recall. We investigate the feasibility of this approach with CuedR, a novel cued-recognition authentication scheme that provides users with multiple cues (visual, verbal, and spatial) and lets them choose the cues that best fit their learning process for later recognition of system-assigned keywords. In our lab study, all 37 of our participants could log in within three attempts one week after registration (mean login time: 38.0 seconds). A pilot study on using multiple CuedR passwords also showed 100% recall within three attempts. Based on our results, we suggest appropriate applications for CuedR, such as financial and e-commerce accounts.
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paper_title: Can indifference make the world greener?

paper_content:

We conducted a natural field experiment to evaluate two resource conservation programs. One intervention consisted of a moral appeal message asking university employees to cut back on printing in general, and to use double-sided printing whenever possible. The other intervention tested whether people׳s tendency to stick with pre-set alternatives is applicable to resource use: at random points in time we changed the default setting on the university printers, from single-sided to double-sided printing. Whereas the moral appeal had no impact, the default change cut paper use by 15 percent. Further analysis adds two important insights. First, we show that defaults influence behavior also in the longer run. Second, we present results indicating that resource efficient defaults have the advantage of avoiding unintended behavioral responses. Overall, our findings send a clear message to anyone concerned about resource conservation: there are potentially large gains to be made from small interventions.
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paper_title: Head-mounted and multi-surface displays support emergency medical teams

paper_content:

Emergency medical teams collaborate to solve problems and take care of patients under time pressure and high cognitive load, in noisy and complex environments. This paper presents preliminary work in the design and evaluation of head-mounted and multi-surface displays in supporting teams with interactive checklists and more generally dynamic cognitive aids.
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paper_title: The Role of Search Result Position and Source Trustworthiness in the Selection of Web Search Results When Using a List or a Grid Interface

paper_content:

Previous research indicates that web users rely to a great extent on the ranking provided by the search engine and predominantly access the first few web pages presented. In case that the information sources presented in the top of the search engine results page (SERP) are of rather low trustworthiness, this might lead to a biased or incomplete view of the topic—especially when dealing with controversial issues. Study 1, thus, systematically investigated whether participants who were asked to search for an unfamiliar and controversial medical issue accessed fewer trustworthy information sources and consequently included less information from trustworthy pages in their argumentation when the search results were ranked from least to most trustworthy on a Google-like SERP than when they were ranked from most to least trustworthy. Results from Study 1 confirmed these assumptions. Furthermore, Study 2 showed that when the same materials were presented in a grid interface, the impact of the position of the sear...
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paper_title: Nudging towards security: developing an application for wireless network selection for android phones

paper_content:

People make security choices on a daily basis without fully considering the security implications of those choices. In this paper we present a prototype application which promotes the choice of secure wireless network options, specifically when users are unfamiliar with the wireless networks available. The app was developed based on behavioural theory, choice architecture and good practices informed by HCI design. The app includes several options to 'nudge' users towards selecting more secure public wireless networks. This paper outlines the development and the results of an evaluation of some of the potential app nudges (specifically, presentation order and colour coding). Colour coding was found to be a powerful influence, less so with the order in which we listed the Wi-Fi networks, although the colour x order combination was most effective. The paper contributes to the body of evidence on the effectiveness of cyber-security interventions to empower the user to make more informed security decisions.
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paper_title: Designing Product Lists for E-commerce: The Effects of Sorting on Consumer Decision Making

paper_content:

One common information display design that appears in nearly all electronic shopping sites is product lists on Web pages. Many electronic shopping sites provide sorting functions for product quality attributes. However, the extant literature has not been particularly insightful on how consumers respond to product lists sorted in different orders (i.e., ascending, descending, and random). Despite the intuitive postulation that products appearing in an early position of a list may draw more attention, it is not evident whether and how different sorting of products in a list affect consumers' purchase decisions. The purpose of this research is to investigate how product sorting influences consumers' decision making. Specifically, the focus is on the effect of sorting by product quality attributes on the importance of quality and price in consumers' product choice and on the formation of their consideration set. Results from the experiment show that, when product quality and price are positively but not perfe...
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paper_title: Mining behavioral economics to design persuasive technology for healthy choices

paper_content:

Influence through information and feedback has been one of the main approaches of persuasive technology. We propose another approach based on behavioral economics research on decision-making. This approach involves designing the presentation and timing of choices to encourage people to make self-beneficial decisions. We applied three behavioral economics persuasion techniques - the default option strategy, the planning strategy, and the asymmetric choice strategy - to promote healthy snacking in the workplace. We tested the strategies in three experimental case studies using a human snack deliverer, a robot, and a snack ordering website. The default and the planning strategies were effective, but they worked differently depending on whether the participants had healthy dietary lifestyles or not. We discuss designs for persuasive technologies that apply behavioral economics.
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paper_title: Improving text passwords through persuasion

paper_content:

Password restriction policies and advice on creating secure passwords have limited effects on password strength. Influencing users to create more secure passwords remains an open problem. We have developed Persuasive Text Passwords (PTP), a text password creation system which leverages Persuasive Technology principles to influence users in creating more secure passwords without sacrificing usability. After users choose a password during creation, PTP improves its security by placing randomly-chosen characters at random positions into the password. Users may shuffle to be presented with randomly-chosen and positioned characters until they find a combination they feel is memorable. In this paper, we present an 83-participant user study testing four PTP variations. Our results show that the PTP variations significantly improved the security of users' passwords. We also found that those participants who had a high number of random characters placed into their passwords would deliberately choose weaker pre-improvement passwords to compensate for the memory load. As a consequence of this compensatory behaviour, there was a limit to the gain in password security achieved by PTP.
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paper_title: Status Quo Bias in Decision Making

paper_content:

Most real decisions, unlike those of economics texts, have a status quo alternative—that is, doing nothing or maintaining one's current or previous decision. A series of decision-making experiments shows that individuals disproportionately stick with the status quo. Data on the selections of health plans and retirement programs by faculty members reveal that the status quo bias is substantial in important real decisions. Economics, psychology, and decision theory provide possible explanations for this bias. Applications are discussed ranging from marketing techniques, to industrial organization, to the advance of science.
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paper_title: Unrealistic optimism about future life events

paper_content:

Two studies investigated the tendency of people to be unrealistically optimistic about future life events. In Study 1, 258 college students estimated how much their own chances of experiencing 42 events differed from the chances of their classmates. Overall, they rated their own chances to be above average for positive events and below average for negative events, ps<.001. Cognitive and motivational considerations led to predictions that degree of desirability, perceived probability, personal experience, perceived controllability, and stereotype salience would influence the amount of optimistic bias evoked by different events. All predictions were supported, although the pattern of effects differed for positive and negative events. Study 2 tested the idea that people are unrealistically optimistic because they focus on factors that improve their own chances of achieving desirable outcomes and fail to realize that others may have just as many factors in their favor. Students listed the factors that they thought influenced their own chances of experiencing eight future events. When such lists were read by a second group of students, the amount of unrealistic optimism shown by this second group for the same eight events decreased significantly, although it was not eliminated.
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paper_title: Towards Designing Persuasive Ambient Visualization

paper_content:

This paper discusses an alternative application area for ambient information systems, coined as ‘persuasive visualization’. It investigates the recent evolution of ambient displays, from simply aiming to inform people about data patterns towards increasing awareness of themes underlying the data. Accordingly, this paper proposes the potential of ambient display techniques to encourage users to modify their behavior. First, the evolution of past ambient display applications is analyzed according to their persuasive capabilities and environmental contexts, ranging from large-scale installations towards more personalized applications of ubiquitous and wearable computing. Accordingly, ambient displays could become a useful platform for unobtrusive, aesthetic applications that can augment our awareness and encourage positive behavior modifications relating to socially relevant issues.
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paper_title: Leading people to longer queries

paper_content:

Although longer queries can produce better results for information seeking tasks, people tend to type short queries. We created an interface designed to encourage people to type longer queries, and evaluated it in two Mechanical Turk experiments. Results suggest that our interface manipulation may be effective for eliciting longer queries.
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paper_title: Children Seen But Not Heard: When Parents Compromise Children's Online Privacy

paper_content:

Children's online privacy has garnered much attention in media, legislation, and industry. Adults are concerned that children may not adequately protect themselves online. However, relatively little discussion has focused on the privacy breaches that may occur to children at the hands of others, namely, their parents and relatives. When adults post information online, they may reveal personal information about their children to other people, online services, data brokers, or surveillant authorities. This information can be gathered in an automated fashion and then linked with other online and offline sources, creating detailed profiles which can be continually enhanced throughout the children's lives. In this paper, we conduct a study to see how widespread these behaviors are among adults on Facebook and Instagram. We use a number of methods. Firstly, we automate a process to examine 2,383 adult users on Facebook for evidence of children in their public photo albums. Using the associated comments in combination with publicly available voter registration records, we are able to infer children's names, faces, birth dates, and addresses. Secondly, in order to understand what additional information is available to Facebook and the users' friends, we survey 357 adult Facebook users about their behaviors and attitudes with regard to posting their children's information online. Thirdly, we analyze 1,089 users on Instagram to infer facts about their children. Finally, we make recommendations for privacy-conscious parents and suggest an interface change through which Facebook can nudge parents towards better stewardship of their children's privacy.
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paper_title: Using personal examples to improve risk communication for security & privacy decisions

paper_content:

IT security systems often attempt to support users in taking a decision by communicating associated risks. However, a lack of efficacy as well as problems with habituation in such systems are well known issues. In this paper, we propose to leverage the rich set of personal data available on smartphones to communicate risks using personalized examples. Examples of private information that may be at risk can draw the users' attention to relevant information for a decision and also improve their response. We present two experiments that validate this approach in the context of Android app permissions. Private information that becomes accessible given certain permissions is displayed when a user wants to install an app, demonstrating the consequences this installation might have. We find that participants made more privacy-conscious choices when deciding which apps to install. Additionally, our results show that our approach causes a negative affect in participants, which makes them pay more attention.
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paper_title: Keymoment: initiating behavior change through friendly friction

paper_content:

To initiate new behavior is challenging, but to maintain this new behavior can be even more so. In this paper, we present Keymoment, a key holder designed to increase physical activity by raising the frequency of taking the bike instead of the car. To accomplish this, it creates friction, but in a meaningful and light way. Keymoment is an example of what we call pleasurable troublemakers -- a genre of interactive things, designed to help people changing themselves. We discuss variations of the Keymoment as well as the general principles, pleasurable troublemakers are based on.
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paper_title: Periodic Prompts and Reminders in Health Promotion and Health Behavior Interventions: Systematic Review

paper_content:

Background: Health behavior interventions using periodic prompts have utilized technology, such as the Internet, that allows messages to be sent to participants in cost-effective ways. To our knowledge, no comprehensive evidence review has been performed specifically to evaluate the effectiveness of communicating regular messages and to examine how characteristics of the prompts change the effectiveness of programs aimed at reminding people to adopt healthy behaviors, maintain those they already practice, and cease unhealthy behaviors. Objective: A systematic literature review was performed to investigate the effectiveness of limited contact interventions targeting weight loss, physical activity, and/or diet that provided periodic prompts regarding behavior change for health promotion. The review sought to identify specific characteristics of these interventions that may be associated with superior results. Methods: Electronic literature searches were performed between February and April, 2008. Articles were included if periodic prompts were used as an intervention or a component of an intervention, a behavioral or biological outcome measure was used, and an ongoing health promotion behavior was targeted. A rating system was applied to each study to provide a quantitative representation of the quality of the evidence provided by each article. Results: There were 19 articles with a combined sample size of 15,655 that met the inclusion criteria, and 11 studies reported positive findings regarding the utility of periodic prompts. Several articles showed enhanced effectiveness when prompts were frequent and personal contact with a counselor was included. Long-term behavior change and health improvements were not examined by this review because of a lack of long-term follow-up in the literature. Conclusions: In light of promising results of most studies, additional research on limited contact interventions targeting health behaviors including weight loss, physical activity, and/or diet is merited that utilizes rigorous methods including control groups; follow-up data collection; and testing of prompt frequencies, specific intervention components, or prompt characteristics. Future research would be especially valuable if it improves understanding of the most effective types of periodic prompts for fostering long-term behavior change in order to maximize use of this tool in limited contact health promotion programs. Specifically, various types of communication technology should be used and evaluated to expand and refine their use. [J Med Internet Res 2009;11(2):e16]
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paper_title: NewsCube: delivering multiple aspects of news to mitigate media bias

paper_content:

The bias in the news media is an inherent flaw of the news production process. The resulting bias often causes a sharp increase in political polarization and in the cost of conflict on social issues such as Iraq war. It is very difficult, if not impossible, for readers to have penetrating views on realities against such bias. This paper presents NewsCube, a novel Internet news service aiming at mitigating the effect of media bias. NewsCube automatically creates and promptly provides readers with multiple classified viewpoints on a news event of interest. As such, it effectively helps readers understand a fact from a plural of viewpoints and formulate their own, more balanced viewpoints. While media bias problem has been studied extensively in communications and social sciences, our work is the first to develop a news service as a solution and study its effect. We discuss the effect of the service through various user studies.
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paper_title: It Is All About Perspective: An Exploration of Mitigating Selective Exposure with Aspect Indicators

paper_content:

Selective exposure, the preferential seeking of confirmatory information, can potentially exacerbate fragmentation of online opinions and lead to biased decisions. We tested whether features that allowed users to better distinguish information about different issue aspects would encourage them to take different perspectives, thereby moderating the negative influence of pre-existing beliefs on information seeking. Using an information aggregator that provided drug related comments, we conducted an experiment to study the impact of aspect indicators (indicating whether the comment was about effectiveness or side effects) on moderating selective exposure. We found that, when participants were asked to decide between medications for high-risk diseases, and had preexisting biased beliefs in their effectiveness (one medication was less effective than the other), without aspect indicators they exhibited selective exposure to both types of comments (effectiveness and side effects) and were biased to choose the medication in confirmation of their pre-existing beliefs. With aspect indicators, we found reduced selective exposure to information about side effects of the medications, and as a result their overall decision bias was mitigated. However, the effect of aspect indicators in reducing selective exposure was moderated by the decision contexts, including the perceived risk of the diseases and whether the aspect was perceived to be critical to the decision.
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paper_title: Confirmation Bias: A Ubiquitous Phenomenon in Many Guises

paper_content:

Confirmation bias, as the term is typically used in the psychological literature, connotes the seeking or interpreting of evidence in ways that are partial to existing beliefs, expectations, or a h...
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paper_title: Decoy Effects in Choice Experiments and Contingent Valuation: Asymmetric Dominance

paper_content:

While a dominated choice involves a situation in which one option clearly dominates another on all relevant dimensions, an asymmetrically dominated choice typically arises where at least two options do not dominate each other and one (but not both) of those options does dominate a third option. We demonstrate that the introduction of such an asymmetrically dominated option can have a significant impact upon choices between non-dominated options within the same choice set for non-market goods. Furthermore, we show that this effect can then translate into significant impacts upon subsequent valuations for those non-dominated options.
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paper_title: On the retrospective assessment of users' experiences over time: memory or actuality?

paper_content:

An alternative paradigm to longitudinal studies of user experience is proposed. We illustrate this paradigm through a number of recent tool-based methods. We conclude by raising a number of challenges that we need to address in order to establish this paradigm as a fruitful alternative to longitudinal studies.
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paper_title: Peak-End Effects on Player Experience in Casual Games

paper_content:

The peak-end rule is a psychological heuristic observing that people's retrospective assessment of an experience is strongly influenced by the intensity of the peak and final moments of that experience. We examine how aspects of game player experience are influenced by peak-end manipulations to the sequence of events in games that are otherwise objectively identical. A first experiment examines players' retrospective assessments of two games (a pattern matching game based on Bejeweled and a point-and-click reaction game) when the sequence of difficulty is manipulated to induce positive, negative and neutral peak-end effects. A second experiment examines assessments of a shootout game in which the balance between challenge and skill is similarly manipulated. Results across the games show that recollection of challenge was strongly influenced by peak-end effects; however, results for fun, enjoyment, and preference to repeat were varied -- sometimes significantly in favour of the hypothesized effects, sometimes insignificant, but never against the hypothesis.
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paper_title: Mining behavioral economics to design persuasive technology for healthy choices

paper_content:

Influence through information and feedback has been one of the main approaches of persuasive technology. We propose another approach based on behavioral economics research on decision-making. This approach involves designing the presentation and timing of choices to encourage people to make self-beneficial decisions. We applied three behavioral economics persuasion techniques - the default option strategy, the planning strategy, and the asymmetric choice strategy - to promote healthy snacking in the workplace. We tested the strategies in three experimental case studies using a human snack deliverer, a robot, and a snack ordering website. The default and the planning strategies were effective, but they worked differently depending on whether the participants had healthy dietary lifestyles or not. We discuss designs for persuasive technologies that apply behavioral economics.
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paper_title: Animation attracts: The attraction effect in an on-line shopping environment

paper_content:

Two studies examine the attraction effect—an inconsistent choice behavior typically observed when consumers are presented with two products (target and competitor), both good for different reasons, and a worse “decoy”—in the context of online consumer decisions with different product displays (animated or static). The experiments, with different participant populations, show that the attraction effect in an online shopping environment depends on the animation format of the products. Experiment 1 (with Italian participants) suggests that the attraction effect is eliminated when target and competitor are both animated and is accentuated when the target is animated and the competitor is static, regardless of whether the decoy is animated or static. Experiment 2 replicates this animation/attraction effect in the United States, where on line shopping is more common than in Italy. The paper concludes with theoretical and practical implications for on line shopping. © 2006 Wiley Periodicals, Inc.
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paper_title: Benevolent deception in human computer interaction

paper_content:

Though it has been asserted that "good design is honest", [42] deception exists throughout human-computer interaction research and practice. Because of the stigma associated with deception - in many cases rightfully so - the research community has focused its energy on eradicating malicious deception, and ignored instances in which deception is positively employed. In this paper we present the notion of benevolent deception, deception aimed at benefitting the user as well as the developer. We frame our discussion using a criminology-inspired model and ground components in various examples. We assert that this provides us with a set of tools and principles that not only helps us with system and interface design, but that opens new research areas. After all, as Cockton claims in his 2004 paper "Value-Centered HCI" [13], "Traditional disciplines have delivered truth. The goal of HCI is to deliver value."
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paper_title: Examining the Peak-End Effects of Subjective Experience

paper_content:

Psychological research has shown that 'peak-end' effects influence people's retrospective evaluation of hedonic and affective experience. Rather than objectively reviewing the total amount of pleasure or pain during an experience, people's evaluation is shaped by the most intense moment (the peak) and the final moment (end). We describe an experiment demonstrating that peak-end effects can influence a user's preference for interaction sequences that are objectively identical in their overall requirements. Participants were asked to choose which of two interactive sequences of five pages they preferred. Both sequences required setting a total of 25 sliders to target values, and differed only in the distribution of the sliders across the five pages -- with one sequence intended to induce positive peak-end effects, the other negative. The study found that manipulating only the peak or the end of the series did not significantly change preference, but that a combined manipulation of both peak and end did lead to significant differences in preference, even though all series had the same overall effort.
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paper_title: THE POWERFUL PLACEBO

paper_content:

Placebos have doubtless been used for centuries by wise physicians as well as by quacks, but it is only recently that recognition of an enquiring kind has been given the clinical circumstance where the use of this tool is essential "... to distinguish pharmacological effects from the effects of suggestion, and... to obtain an unbiased assessment of the result of experiment." It is interesting that Pepper could say as recently as 10 years ago "apparently there has never been a paper published discussing [primarily] the important subject of the placebo." In 1953 Gaddum1said: Such tablets are sometimes called placebos, but it is better to call them dummies. According to the Shorter Oxford Dictionary the word placebo has been used since 1811 to mean a medicine given more to please than to benefit the patient. Dummy tablets are not particularly noted for the pleasure which they give to their recipients.
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paper_title: The cake can be a lie: placebos as persuasive videogame elements

paper_content:

This paper presents a research which aimed at exploring the effects that videogame temporary reinforcements (commonly known in the domain as power-ups or bonuses) have on players from a physiological and performance perspective. We specifically address this type of mechanic from a persuasion point-of-view, questioning whether the knowledge of the existence of such elements within a game is sufficient to provoke any alterations on the player, regardless of a real reinforcement being provided. Testing was performed with two different games, and a total of sixty users to validate our findings. Results show that different persuasive technique designs can effectively be used to improve player performance as well as regulating their physiological state into a decreased stress status. We provide a brief analysis of these results along with a discussion regarding the design implications and opportunities of these findings and how they are related with existing videogame literature.
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paper_title: Designing Closeness to Increase Gamers' Performance

paper_content:

Designers often make use of social comparisons to motivate people to perform better. In this paper, we present the concept of closeness to comparison to improve the efficacy of social comparison feedback. Specifically, we test two design strategies related to closeness: (1) comparing users to a target described as a similarly experienced player and (2) adjusting the visual representation of performance so player scores appear closer to the comparison target. We evaluate the effects of these strategies for social comparison on player performance in an online game. In a controlled experiment with 425 participants, both feedback techniques improved game performance, but only for experienced players. We conclude with design implications for helping designers create social comparisons that motivate higher game performance.
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paper_title: Using Delboeuf's illusion to improve point and click performance for older adults

paper_content:

Older computer users often exhibit poorer performance in point and click tasks on a computer than younger adults. This paper reports on the first phase of research that examines whether a visual illusion that makes an object appear to be larger (Delboeuf's Illusion), can help to improve point and click performance for older computer users. In this first phase, we look at the effect sizes for different configurations of the Delboeuf illusion. The study finds that the target size is overestimated by 8% for both older and younger adults in one configuration, and 12% for older adults in another configuration. The results will inform the design of a second phase, in which the configurations which demonstrate the largest effects will be investigated using a Fitts'-style study of pointing performance.
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paper_title: Mindless computing: designing technologies to subtly influence behavior

paper_content:

Persuasive technologies aim to influence user's behaviors. In order to be effective, many of the persuasive technologies developed so far relies on user's motivation and ability, which is highly variable and often the reason behind the failure of such technology. In this paper, we present the concept of Mindless Computing, which is a new approach to persuasive technology design. Mindless Computing leverages theories and concepts from psychology and behavioral economics into the design of technologies for behavior change. We show through a systematic review that most of the current persuasive technologies do not utilize the fast and automatic mental processes for behavioral change and there is an opportunity for persuasive technology designers to develop systems that are less reliant on user's motivation and ability. We describe two examples of mindless technologies and present pilot studies with encouraging results. Finally, we discuss design guidelines and considerations for developing this type of persuasive technology.
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paper_title: Pinteresce: Exploring Reminiscence as an Incentive to Digital Reciprocity for Older Adults

paper_content:

Sustaining remote communication across generations is a continuing problem, due to the increasing popularity of online communication. Participation in online platforms is advantageous for seniors wishing to connect with younger generations, yet reciprocity on these platforms is a challenge for older adults. Barriers include the cognitive overload of existing mainstream interfaces and a lack of engaging content. In this paper we propose Pinteresce, a tool leveraging family-generated reminiscence prompts to encourage seniors' participation in the online community, Pinterest. The system provides an intuitive interface for communicating across age groups to promote reciprocal engagement with online content.
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paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
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paper_title: Tools for predicting drop-off in large online classes

paper_content:

This paper describes two diagnostic tools to predict students are at risk of dropping out from an online class. While thousands of students have been attracted to large online classes, keeping them motivated has been challenging. Experiments on a large, online HCI class suggest that the tools these paper introduces can help identify students who will not complete assignments, with an F1 score of 0.46 and 0.73 three days before the assignment due date.
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paper_title: The Escalation of Commitment To a Course of Action.

paper_content:

There are many instances in which individuals can become locked into a costly course of action. Because it is often possible for persons who have suffered a setback to recoup their losses through an even greater commitment of resources to the same course of action, a cycle of escalating commitment can be produced. In this paper, I review recent research on the escalation of commitment and try to integrate its complex and often conflicting determinants.
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paper_title: The spotlight effect in social judgment: An egocentric bias in estimates of the salience of one’s own actions and appearance

paper_content:

This research provides evidence that people overestimate the extent to which their actions and appearance are noted by others, a phenomenon dubbed the spotlight effect. In Studies 1 and 2, participants who were asked to don a T-shirt depicting either a flattering or potentially embarrassing image overestimated the number of observers who would be able to recall what was pictured on the shirt. In Study 3, participants in a group discussion overestimated how prominent their positive and negative utterances were to their fellow discussants. Studies 4 and 5 provide evidence supporting an anchoring-and-adjustment interpretation of the spotlight effect. In particular, people appear to anchor on their own rich phenomenological experience and then adjust--insufficiently--to take into account the perspective of others. The discussion focuses on the manifestations and implications of the spotlight effect across a host of everyday social phenomena.
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paper_title: Social toothbrush: fostering family nudging around tooth brushing habits

paper_content:

The earlier in life an individual adopts healthy practices the more impact those practices have on the long term. In this paper we present Social Toothbrush, a hardware plugin for electric toothbrushes that aims to induce proper tooth brushing behaviors on young children and adults. Social Toothbrush does so by taking advantage of family communication and coordination practices to encourage healthy practices. We first describe the theoretical grounding of our design process, Social Translucence, followed by the design and development of Social Toothbrush.
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paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
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paper_title: Social translucence: an approach to designing systems that support social processes

paper_content:

We are interested in desiging systems that support communication and collaboration among large groups of people over computing networks. We begin by asking what properties of the physical world support graceful human-human communication in face-to-face situations, and argue that it is possible to design digital systems that support coherent behavior by making participants and their activites visible to one another. We call such systems “socially translucent systems” and suggest that they have three characteristics—visbility, awareness, and accountability—which enable people to draw upon their experience and expertise to structure their interactions with one another. To motivate and focus our ideas we develop a vision of knowledge communities, conversationally based systems that support the creation, management and reuse of knowledge in a social context. We describe our experience in designing and deploying one layer of functionality for knowledge communities, embodied in a working system called “Barbie” and discuss research issues raised by a socially translucent approach to design.
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paper_title: "We've bin watching you": designing for reflection and social persuasion to promote sustainable lifestyles

paper_content:

BinCam is a social persuasive system to motivate reflection and behavioral change in the food waste and recycling habits of young adults. The system replaces an existing kitchen refuse bin and automatically logs disposed of items through digital images captured by a smart phone installed on the underside of the bin lid. Captured images are uploaded to a BinCam application on Facebook where they can be explored by all users of the BinCam system. Engagement with BinCam is designed to fit into the existing structure of users' everyday life, with the intention that reflection on waste and recycling becomes a playful and shared group activity. Results of a user study reveal an increase in both users' awareness of, and reflection about, their waste management and their motivation to improve their waste-related skills. With BinCam, we also explore informational and normative social influences as a source of change (e.g., socially evoked feelings of 'guilt' for non-recycling or food disposal), which has to date been underexplored in persuasive HCI. Design implications for reflection and social persuasion are proposed.
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paper_title: Designing Closeness to Increase Gamers' Performance

paper_content:

Designers often make use of social comparisons to motivate people to perform better. In this paper, we present the concept of closeness to comparison to improve the efficacy of social comparison feedback. Specifically, we test two design strategies related to closeness: (1) comparing users to a target described as a similarly experienced player and (2) adjusting the visual representation of performance so player scores appear closer to the comparison target. We evaluate the effects of these strategies for social comparison on player performance in an online game. In a controlled experiment with 425 participants, both feedback techniques improved game performance, but only for experienced players. We conclude with design implications for helping designers create social comparisons that motivate higher game performance.
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paper_title: Social responses in mobile messaging: influence strategies, self-disclosure, and source orientation

paper_content:

This paper reports on a direct test of social responses to communication technologies theory (SRCT) with mobile messaging. SRCT predicts that people will mindlessly respond to computers in social ways that mirror their responses to humans. A field experiment (N=71) using participants' own mobile phones compared three influence strategies (direct request, flattery, and social norms) in the context of asking intimate questions of participants. These messages came from either an ostensibly human or computer sender. Flattery significantly increased self-disclosure when ostensibly sent by a human, but not when from a computer. The interaction effect for sender and influence strategy is inconsistent with SRCT's predictions. Implications for theories of source orientation, research methods, and future research are discussed.
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paper_title: Exploring the design space of glanceable feedback for physical activity trackers

paper_content:

Recent research reveals over 70% of the usage of physical activity trackers to be driven by glances -- brief, 5-second sessions where individuals check ongoing activity levels with no further interaction. This raises a question as to how to best design glanceable behavioral feedback. We first set out to explore the design space of glanceable feedback in physical activity trackers, which resulted in 21 unique concepts and 6 design qualities: being abstract, integrating with existing activities, supporting comparisons to targets and norms, being actionable, having the capacity to lead to checking habits and to act as a proxy to further engagement. Second, we prototyped four of the concepts and deployed them in the wild to better understand how different types of glanceable behavioral feedback affect user engagement and physical activity. We found significant differences among the prototypes, all in all, highlighting the surprisingly strong effect glanceable feedback has on individuals' behaviors.
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paper_title: A Theory of Social Comparison Processes

paper_content:

Hypothesis I: There exists, in the human organism, a drive to evaluate his opinions and his abilities. While opinions and abilities may, at first glance, seem to be quite different things, there is a close functional tie between them. They act together in the manner in which they affect behavior. A person’s cognition (his opinions and beliefs) about the situation in which he exists and his appraisals of what he is capable of doing (his evaluation of his abilities) will together have bearing on his behavior. The holding of incorrect opinions and/or inaccurate appraisals of one’s abilities can be punishing or even fatal in many situations. It is necessary, before we proceed, to clarify the distinction between opinions and evaluations of abilities since at first glance it may seem that one’s evaluation of one’s own ability is an opinion about it. Abilities are of course manifested only through performance which is assumed to depend upon the particular ability. The clarity of the manifestation or performance can vary from instances where there is no clear ordering criterion of the ability to instances where the performance which reflects the ability can be clearly ordered. In the former case, the evaluation of the ability does function like other opinions which are not directly testable in “objective reality’. For example, a person’s evaluation of his ability to write poetry will depend to a large extent on the opinions which others have of his ability to write poetry. In cases where the criterion is unambiguous and can be clearly ordered, this furnishes an objective reality for the evaluation of one’s ability so that it depends less on the opinions of other persons and depends more on actual comparison of one’s performance with the performance of others. Thus, if a person evaluates his running ability, he will do so by comparing his time to run some distance with the times that other persons have taken. In the following pages, when we talk about evaluating an ability, we shall mean specifically the evaluation of that ability in situations where the performance is unambiguous and is known. Most situations in real life will, of course, present situations which are a mixture of opinion and ability evaluation. In a previous article (7) the author posited the existence of a drive to determine whether or not one’s opinions were “correct”. We are here stating that this same drive also produces behavior in people oriented toward obtaining an accurate appraisal of their abilities. The behavioral implication of the existence of such a drive is that we would expect to observe behaviour on the part of persons which enables them to ascertain whether or not their opinions are correct and also behavior which enables them accurately to evaluate their abilities. It is consequently
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paper_title: Exploring the design space of glanceable feedback for physical activity trackers

paper_content:

Recent research reveals over 70% of the usage of physical activity trackers to be driven by glances -- brief, 5-second sessions where individuals check ongoing activity levels with no further interaction. This raises a question as to how to best design glanceable behavioral feedback. We first set out to explore the design space of glanceable feedback in physical activity trackers, which resulted in 21 unique concepts and 6 design qualities: being abstract, integrating with existing activities, supporting comparisons to targets and norms, being actionable, having the capacity to lead to checking habits and to act as a proxy to further engagement. Second, we prototyped four of the concepts and deployed them in the wild to better understand how different types of glanceable behavioral feedback affect user engagement and physical activity. We found significant differences among the prototypes, all in all, highlighting the surprisingly strong effect glanceable feedback has on individuals' behaviors.
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paper_title: Personalizing persuasive technologies : explicit and implicit personalization using persuasion profiles

paper_content:

This paper discusses how persuasive technologies can be made adaptive to users. We present persuasion profiling as a method to personalize the persuasive messages used by a system to influence its users. This type of personalization can be based on explicit measures of users? tendencies to comply to distinct persuasive strategies: measures based on standardized questionnaire scores of users. However, persuasion profiling can also be implemented using implicit, behavioral measures of user traits. We present three case studies involving the design, implementation, and field deployment of personalized persuasive technologies, and we detail four design requirements. In each case study we show how these design requirements are implemented. In the discussion we highlight avenues for future research in the field of adaptive persuasive technologies. Author-HighlightsPersuasive technologies can be more effective if they are personalized.We introduce persuasion profiles to personalize persuasive messages.Persuasion profiles can be effective using implicit or explicit measures.In three case studies we show the effects of personalized persuasion.
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paper_title: Construal level theory of psychological distance

paper_content:

People are capable of thinking about the future, the past, remote locations, another person’s perspective, and counterfactual alternatives. Without denying the uniqueness of each process, it is proposed that they constitute different forms of traversing psychological distance. Psychological distance is egocentric: Its reference point is the self in the here and now, and the different ways in which an object might be removed from that point—in time, in space, in social distance, and in hypotheticality—constitute different distance dimensions. Transcending the self in the here and now entails mental construal, and the farther removed an object is from direct experience, the higher (more abstract) the level of construal of that object. Supporting this analysis, research shows (a) that the various distances are cognitively related to each other, (b) that they similarly influence and are influenced by level of mental construal, and (c) that they similarly affect prediction, preference, and action.
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paper_title: Anomalies: The endowment effect, loss aversion, and status quo bias

paper_content:

most (all?) behavior can be explained by assuming that agents have stable, well-defined preferences and make rational choices consistent with those preferences in markets that (eventually) clear. An empirical result qualifies as an anomaly if it is difficult to "rationalize," or if implausible assumptions are necessary to explain it within the paradigm. This column presents a series of such anomalies. Readers are invited to suggest topics for future columns by
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paper_title: Enhancing human responses to climate change risks through simulated flooding experiences

paper_content:

Delta areas are threatened by global climate change. The general aims of our research were (1) to increase our understanding of climate and flood risk perceptions and the factors that influence these judgments, and (2) to seek for interventions that can contribute to a realistic assessment by laypersons of long-term flooding risks. We argue that awareness of one’s own vulnerability to future flooding and insights into the effectiveness of coping strategies is driven by direct flooding experiences. In the current research multimodal sensory stimulation by means of interactive 3D technology is used to simulate direct flooding experiences at the experiential or sensory level, thereby going beyond traditional persuasion attempts using fear-evoking images. Our results suggest that future communication efforts should not only use these new technologies to transfer knowledge about effective coping strategies and flooding risks, but should especially be directed towards residents living in flood prone areas, but who lack direct flooding experiences as their guiding principle.
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paper_title: Tailoring Web Pages for Persuasion on Prevention Topics: Message Framing, Color Priming, and Gender

paper_content:

On the Web, as in more traditional influence contexts, the most effective persuasive strategies often depend on the individual characteristics of the message recipient. Unfortunately, most persuasive technology applications currently employ a one-size-fits-all approach to interventions. The study we illustrate investigates two different techniques message framing and color priming that can be used in tailoring a persuasive Web page about a prevention topic. The findings of our study highlight interactive effects between message framing and color priming, and advance the results in the literature by showing that red enhances the effects of framing in a gender-based fashion. The obtained results also provide practical guidance for automatic tailoring of persuasive Web pages about prevention topics, suggesting a strategy based on gender, an information about the user that is typically readily available in social network profiles, and other Web sites to which people register.
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paper_title: Informing and Improving Retirement Saving Performance using Behavioral Economics Theory-driven User Interfaces

paper_content:

Can human-computer interaction help people make informed and effective decisions about their retirement savings? We applied the behavioral economic theories of endowment effect and loss aversion to the design of novel retirement saving user interfaces. To examine effectiveness, we conducted an experiment in which 487 participants were exposed to one of three experimental user interface designs of a retirement saving simulator, representing endowment effect, loss aversion and control. Users made 34 yearly asset allocation decisions. We found that designs informed by the endowment effect and loss aversion theories and which communicated to savers the long-term implications of their asset allocation choices, led users to adjust their behavior, make larger and more frequent asset allocation changes, and achieve their saving goals more effectively.
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paper_title: A long-term study of user experience towards interaction designs that support behavior change

paper_content:

Many researches on interaction design that supports users' behavior change in everyday life are studied recently especially in the domain of pervasive technology. However, not much attention has been paid to long-term effects on users in such cases. This paper presents our initial work of a long-term (8 month) study of users' self-report of experiences with an ambient dashboard feedback system in an automobile called Eco-driving system. It was notable that user satisfaction changed positively following active self-efforts made by users to understand the system after the negative shift due to initial disappointment. This work will be a first step to build a framework of how users accept systems designed to persuade them to change behavior over time.
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paper_title: EcoMeal: A Smart Tray for Promoting Healthy Dietary Habits

paper_content:

Dietary habits greatly influence one's health. Particularly, for the patients who suffer from metabolic syndrome, maintaining a healthy dietary habit is crucial to their health. In this paper, we aim to study the dietary behavior of such patients and design a system that can support their difficulties during food plating and eating process. We implemented a prototype to support the patient's eating speed, food portion control and calorie/sodium management. The preliminary evaluation results show both positive and negative aspects of our approach.
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paper_title: The Smart Steering Wheel Cover: Motivating Safe and Efficient Driving

paper_content:

The Smart Steering Wheel Cover is an in-vehicle system designed to enhance driving experiences to be safer and more efficient. It collects data from the driver's smartphone accelerometer to detect how fast the driver is accelerating and braking. The smoothness of the driving correlates with fuel economy: the less aggressive is the driver's behaviour, the less fuel the vehicle consumes. The feedback is communicated to the driver in terms of vibration as warning of poor behaviour and gradual change of light as a reward to motivate constant fuel-efficient behaviour. The physical buttons embedded in the steering wheel cover allow the driver to control their phones straight from the steering wheel without having to compromise safety.
---
paper_title: Name that tune: musicons as reminders in the home

paper_content:

In this paper we argue that Musicons, short samples from pieces of music are a useful way to present private but memorable reminder messages. We investigated accuracy, memorability and response times for short, medium, and long Musicons. User performance on the Musicons was also compared to short spoken reminders. The study consisted of two sessions a week apart. Quantitative measures were augmented with qualitative questions about associations and memories. Overall, participants achieved a high level of accuracy (89%) on the Musicons. Recognition was stable at 90% or better across sessions for users who were able to construct meaningful links between Musicons and the associated tasks. Optimal response times were achieved for medium-length 0.5 sec. Musicons. We conclude that Musicons are a viable option for alarms and notifications that combine the high learnability of Auditory Icons with the more private nature of Earcons.
---
paper_title: Exploring the Effects of Strategy and Arousal of Cueing in Computer-Human Persuasion

paper_content:

In this paper, we explore how different strategy (explicit vs. implicit) and arousal (high vs. low) of cueing influence the process of Computer-Human Persuasion. In particular, we study the impact of various combinations of text-based reminder and screen motions at different speed on the attention, comprehension, yielding, retention, as well as perception of heavy computer users in terms of the need of stretch and change sitting posture. Results suggest that hybrid cueing mechanics, especially with low arousal, were more effective and acceptable in general, while high-arousal cueing may be more suitable for less motivated users.
---
paper_title: WalkMinder: encouraging an active lifestyle using mobile phone interruptions

paper_content:

Medical research suggests that avoiding lengthy periods of physical inactivity can have significant health benefits. The pervasive nature of mobile phones increasingly allows individuals to track and measure their own physical activity thus creating opportunities for them to reflect on their behavior and make informed changes. In this work, we investigated two mechanisms for encouraging a more active lifestyle: a glanceable display of an individual's level of physical activity and mobile phone vibrations to interrupt extended periods of inactivity. We found that both mechanisms can help users become more aware of their activity patterns but may be ignored unless coupled with concrete advice on how to incorporate active moments into their day.
---
paper_title: Breakout: predicting and breaking sedentary behaviour at work

paper_content:

We present BreakOut, a desktop system that infers an individual's posture, stress levels, and engagement with computer related tasks with the goal of recommending a break of sedentary behaviour at appropriate times. We present an Experience Sampling study that attempted to evaluate BreakOut's ability to infer users' posture and stress from a single webcamera as well as their engagement from keyboard and mouse activity. We conclude with the description of an ambient artistic display as well as an intuitive gestural interaction technique that enables the user to interact with BreakOut with minimal cognitive resources.
---
paper_title: Breakaway: an ambient display designed to change human behavior

paper_content:

We present Breakaway, an ambient display that encourages people, whose job requires them to sit for long periods of time, to take breaks more frequently. Breakaway uses the information from sensors placed on an office chair to communicate in a non-obtrusive manner how long the user has been sitting. Breakaway is a small sculpture placed on the desk. Its design is inspired by animation arts and theater, which rely heavily on body language to express emotions. Its shape and movement reflect the form of the human body; an upright position reflecting the body's refreshed pose, and a slouching position reflecting the body's pose after sitting for a long time. An initial evaluation shows a correlation between the movement of the sculpture and when participants took breaks, suggesting that ambient displays that make use of aesthetic and lifelike form might be promising for making positive changes in human behavior.
---
paper_title: Ambient influence: can twinkly lights lure and abstract representations trigger behavioral change?

paper_content:

Can ubiquitous technologies be designed to nudge people to change their behavior? If so, how? We describe an ambient installation that was intended to help people decide - and to encourage them to reflect - when confronted with a choice. In this particular case, it was whether to take the stairs or the elevator in their place of work. The rationale was to push people towards a desired behavior at the point of decision-making and to reflect upon theirs and others' aggregate behavior. We describe the ambient displays that were developed and the prototyping studies in which they were evaluated. The findings from an in-the-wild study are then presented. They reveal that even though people said they were not aware of changing their behavior, logged data of their actual behavior showed a significant change. We discuss these mixed findings in relation to whether ambient displays can influence at an unconscious or conscious level.
---
paper_title: Behavioral science-informed technology interventions for change in residential energy consumption

paper_content:

Behavior change represents an important new approach to addressing the energy crisis. Utility companies and private companies are deploying sensor-based power meters and related residential electricity monitoring technologies with the view that monitoring energy use will eventually result in a reduction in energy consumption. The success of these technologies depends largely on homeowners responding to the data with appropriate changes in their consumption behavior. Most energy feedback interfaces, however, have not been designed through a human-centered process and display data in ways that are unlikely to change behavior. Our proposal is to design interactive interfaces that combine a deeply human-centered process with insights from behavioral economics to reduce residential energy consumption. This paper describes our current research to develop and evaluate interactive interfaces based on three motivational categories: cognitive, social, and affective.
---
paper_title: Subliminal priming and persuasion: Striking while the iron is hot

paper_content:

Three studies demonstrated that subliminally priming a goal-relevant cognition (thirst in Studies 1 and 2; sadness in Study 3) influenced behavior (in Study 1) and enhanced the persuasiveness of an ad targeting the goal (in Studies 2 and 3) when people were motivated to pursue the goal (when they were thirsty in Studies 1 and 2; when they expected to interact with another person in Study 3). These results suggest that subliminal priming can be used to enhance persuasion, but only when certain conditions are met. Both the priming of goal-relevant cognitions and the motive to pursue the goal were necessary for ads targeting the goal to be more persuasive. The implications of these results for the role of functionality in subliminal priming and for the use and abuse of subliminal priming in persuasion are discussed.
---
paper_title: Covert Persuasive Technologies: Bringing Subliminal Cues to Human-Computer Interaction

paper_content:

The capability of machines to covertly persuade humans is both exciting and ethically concerning. In the present study we aim to bring subliminal masked stimulus paradigms to realistic environments, through Virtual Environments. The goal is to test if such paradigms are applicable to realistic setups while identifying the major challenges when doing so. We designed a study in which the user performed a realistic selection task in a virtual kitchen. For trials below one-second reaction time, we report significant effect of subliminal cues on the selection behavior. We conclude the study with a discussion of the challenges of bringing subliminal cueing paradigms to realistic HCI setups. Ethical concerns when designing covertly persuasive systems are discussed as well.
---
paper_title: Subliminal Priming of Nonconscious Goals on Smartphones

paper_content:

We present a theoretical justification for and design of an experiment to explore the use of subliminal priming of nonconscious goals on smartphones to achieve behaviour change.
---
paper_title: On the Design of Subly : Instilling Behavior Change During Web Surfing Through Subliminal Priming

paper_content:

With 50% of people spending over 6 h per day surfing the web, web browsers offer a promising platform for the delivery of behavior change interventions. One technique might be subliminal priming of behavioral concepts (e.g., walking). This paper presents Subly, an open-source plugin for Google’s Chrome browser that primes behavioral concepts through slight emphasis on words and phrases as people browse the Internet. Such priming interventions might be employed across several domains, such as breaking sedentary activity, promoting safe use of the Internet among minors, promoting civil discourse and breaking undesirable online habits such excessive use of social media. We present two studies with Subly: one that identifies the threshold of subliminal perception and one that demonstrates the efficacy of Subly in a picture-selection task. We conclude with opportunities and ethical considerations arising from the future use of Subly to achieve behavior change.
---
paper_title: Changing the default to promote influenza vaccination among health care workers

paper_content:

BACKGROUND ::: The prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure. ::: ::: ::: METHODS ::: HCWs were randomly assigned to one of two conditions. In the opt-out condition (N=61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N=61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated. ::: ::: ::: RESULTS ::: The findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated. ::: ::: ::: CONCLUSION ::: To change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.
---
paper_title: Children Seen But Not Heard: When Parents Compromise Children's Online Privacy

paper_content:

Children's online privacy has garnered much attention in media, legislation, and industry. Adults are concerned that children may not adequately protect themselves online. However, relatively little discussion has focused on the privacy breaches that may occur to children at the hands of others, namely, their parents and relatives. When adults post information online, they may reveal personal information about their children to other people, online services, data brokers, or surveillant authorities. This information can be gathered in an automated fashion and then linked with other online and offline sources, creating detailed profiles which can be continually enhanced throughout the children's lives. In this paper, we conduct a study to see how widespread these behaviors are among adults on Facebook and Instagram. We use a number of methods. Firstly, we automate a process to examine 2,383 adult users on Facebook for evidence of children in their public photo albums. Using the associated comments in combination with publicly available voter registration records, we are able to infer children's names, faces, birth dates, and addresses. Secondly, in order to understand what additional information is available to Facebook and the users' friends, we survey 357 adult Facebook users about their behaviors and attitudes with regard to posting their children's information online. Thirdly, we analyze 1,089 users on Instagram to infer facts about their children. Finally, we make recommendations for privacy-conscious parents and suggest an interface change through which Facebook can nudge parents towards better stewardship of their children's privacy.
---
paper_title: Ambient influence: can twinkly lights lure and abstract representations trigger behavioral change?

paper_content:

Can ubiquitous technologies be designed to nudge people to change their behavior? If so, how? We describe an ambient installation that was intended to help people decide - and to encourage them to reflect - when confronted with a choice. In this particular case, it was whether to take the stairs or the elevator in their place of work. The rationale was to push people towards a desired behavior at the point of decision-making and to reflect upon theirs and others' aggregate behavior. We describe the ambient displays that were developed and the prototyping studies in which they were evaluated. The findings from an in-the-wild study are then presented. They reveal that even though people said they were not aware of changing their behavior, logged data of their actual behavior showed a significant change. We discuss these mixed findings in relation to whether ambient displays can influence at an unconscious or conscious level.
---
paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
---
paper_title: Can indifference make the world greener?

paper_content:

We conducted a natural field experiment to evaluate two resource conservation programs. One intervention consisted of a moral appeal message asking university employees to cut back on printing in general, and to use double-sided printing whenever possible. The other intervention tested whether people׳s tendency to stick with pre-set alternatives is applicable to resource use: at random points in time we changed the default setting on the university printers, from single-sided to double-sided printing. Whereas the moral appeal had no impact, the default change cut paper use by 15 percent. Further analysis adds two important insights. First, we show that defaults influence behavior also in the longer run. Second, we present results indicating that resource efficient defaults have the advantage of avoiding unintended behavioral responses. Overall, our findings send a clear message to anyone concerned about resource conservation: there are potentially large gains to be made from small interventions.
---
paper_title: Ambient influence: can twinkly lights lure and abstract representations trigger behavioral change?

paper_content:

Can ubiquitous technologies be designed to nudge people to change their behavior? If so, how? We describe an ambient installation that was intended to help people decide - and to encourage them to reflect - when confronted with a choice. In this particular case, it was whether to take the stairs or the elevator in their place of work. The rationale was to push people towards a desired behavior at the point of decision-making and to reflect upon theirs and others' aggregate behavior. We describe the ambient displays that were developed and the prototyping studies in which they were evaluated. The findings from an in-the-wild study are then presented. They reveal that even though people said they were not aware of changing their behavior, logged data of their actual behavior showed a significant change. We discuss these mixed findings in relation to whether ambient displays can influence at an unconscious or conscious level.
---
paper_title: Mining behavioral economics to design persuasive technology for healthy choices

paper_content:

Influence through information and feedback has been one of the main approaches of persuasive technology. We propose another approach based on behavioral economics research on decision-making. This approach involves designing the presentation and timing of choices to encourage people to make self-beneficial decisions. We applied three behavioral economics persuasion techniques - the default option strategy, the planning strategy, and the asymmetric choice strategy - to promote healthy snacking in the workplace. We tested the strategies in three experimental case studies using a human snack deliverer, a robot, and a snack ordering website. The default and the planning strategies were effective, but they worked differently depending on whether the participants had healthy dietary lifestyles or not. We discuss designs for persuasive technologies that apply behavioral economics.
---
paper_title: Covert Persuasive Technologies: Bringing Subliminal Cues to Human-Computer Interaction

paper_content:

The capability of machines to covertly persuade humans is both exciting and ethically concerning. In the present study we aim to bring subliminal masked stimulus paradigms to realistic environments, through Virtual Environments. The goal is to test if such paradigms are applicable to realistic setups while identifying the major challenges when doing so. We designed a study in which the user performed a realistic selection task in a virtual kitchen. For trials below one-second reaction time, we report significant effect of subliminal cues on the selection behavior. We conclude the study with a discussion of the challenges of bringing subliminal cueing paradigms to realistic HCI setups. Ethical concerns when designing covertly persuasive systems are discussed as well.
---
paper_title: The cake can be a lie: placebos as persuasive videogame elements

paper_content:

This paper presents a research which aimed at exploring the effects that videogame temporary reinforcements (commonly known in the domain as power-ups or bonuses) have on players from a physiological and performance perspective. We specifically address this type of mechanic from a persuasion point-of-view, questioning whether the knowledge of the existence of such elements within a game is sufficient to provoke any alterations on the player, regardless of a real reinforcement being provided. Testing was performed with two different games, and a total of sixty users to validate our findings. Results show that different persuasive technique designs can effectively be used to improve player performance as well as regulating their physiological state into a decreased stress status. We provide a brief analysis of these results along with a discussion regarding the design implications and opportunities of these findings and how they are related with existing videogame literature.
---
paper_title: Nudges That Fail

paper_content:

Why are some nudges ineffective, or at least less effective than choice architects hope and expect? Focusing primarily on default rules, this essay emphasizes two reasons. The first involves strong antecedent preferences on the part of choosers. The second involves successful “counternudges,” which persuade people to choose in a way that confounds the efforts of choice architects. Nudges might also be ineffective, and less effective than expected, for five other reasons. (1) Some nudges produce confusion on the part of the target audience. (2) Some nudges have only short-term effects. (3) Some nudges produce “reactance” (though this appears to be rare) (4) Some nudges are based on an inaccurate (though initially plausible) understanding on the part of choice architects of what kinds of choice architecture will move people in particular contexts. (5) Some nudges produce compensating behavior, resulting in no net effect. When a nudge turns out to be insufficiently effective, choice architects have three potential responses: (1) Do nothing; (2) nudge better (or different); and (3) fortify the effects of the nudge, perhaps through counter-counternudges, perhaps through incentives, mandates, or bans.
---
paper_title: Can We Nudge Users Toward Better Password Management?: An Initial Study

paper_content:

Nudge theory has been widely used in government and health interventions for the subtlety with which it positively influences choices. But, can this gentle nudge influence users to exhibit secure online account behaviors? And further, which of the nudge types is most effective? We conducted a between-subjects experiment with five conditions, plus a control, in which participants (n = 263) experienced different types of nudges (incentives, norms, default, salience, ego) before indicating their comfort levels with an auto-generated password and intentions to create a new password. Results show the salience nudge most effectively reduced one's comfort level with keeping the auto-generated password. These preliminary findings imply nudges using multiple psychological effects could serve as important design cues, thereby making intended behaviors easy to perform.
---
paper_title: Effects of Public Commitments and Accountability in a Technology-Supported Physical Activity Intervention

paper_content:

Walking and other forms of physical activity have many health benefits, but people often fail to follow through on their own goals of being more active. To address gaps in current understanding of how to design technology-supported physical activity interventions, we conducted a randomized field experiment of a commitment device: making public announcements. In a control condition, weekly commitments were kept private. In two treatment conditions, they were announced on Facebook and by email. In one of the two, the announcements also included results: whether the previous week's commitment was kept. We find that, with or without public results, these posts can elicit supportive replies from the poster's social networks. People in both public announcements conditions were less likely to make commitments. We conclude that the prospect of public accountability may suppress the making of commitments in a way that counteracts the benefits of that accountability. Designers will need to address this limitation in order to make effective use of public accountability as a commitment device.
---
paper_title: Changing the default to promote influenza vaccination among health care workers

paper_content:

BACKGROUND ::: The prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure. ::: ::: ::: METHODS ::: HCWs were randomly assigned to one of two conditions. In the opt-out condition (N=61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N=61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated. ::: ::: ::: RESULTS ::: The findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated. ::: ::: ::: CONCLUSION ::: To change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.
---
paper_title: Exploring the design space of glanceable feedback for physical activity trackers

paper_content:

Recent research reveals over 70% of the usage of physical activity trackers to be driven by glances -- brief, 5-second sessions where individuals check ongoing activity levels with no further interaction. This raises a question as to how to best design glanceable behavioral feedback. We first set out to explore the design space of glanceable feedback in physical activity trackers, which resulted in 21 unique concepts and 6 design qualities: being abstract, integrating with existing activities, supporting comparisons to targets and norms, being actionable, having the capacity to lead to checking habits and to act as a proxy to further engagement. Second, we prototyped four of the concepts and deployed them in the wild to better understand how different types of glanceable behavioral feedback affect user engagement and physical activity. We found significant differences among the prototypes, all in all, highlighting the surprisingly strong effect glanceable feedback has on individuals' behaviors.
---
paper_title: Changing the default to promote influenza vaccination among health care workers

paper_content:

BACKGROUND ::: The prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure. ::: ::: ::: METHODS ::: HCWs were randomly assigned to one of two conditions. In the opt-out condition (N=61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N=61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated. ::: ::: ::: RESULTS ::: The findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated. ::: ::: ::: CONCLUSION ::: To change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.
---
paper_title: Examining the Peak-End Effects of Subjective Experience

paper_content:

Psychological research has shown that 'peak-end' effects influence people's retrospective evaluation of hedonic and affective experience. Rather than objectively reviewing the total amount of pleasure or pain during an experience, people's evaluation is shaped by the most intense moment (the peak) and the final moment (end). We describe an experiment demonstrating that peak-end effects can influence a user's preference for interaction sequences that are objectively identical in their overall requirements. Participants were asked to choose which of two interactive sequences of five pages they preferred. Both sequences required setting a total of 25 sliders to target values, and differed only in the distribution of the sliders across the five pages -- with one sequence intended to induce positive peak-end effects, the other negative. The study found that manipulating only the peak or the end of the series did not significantly change preference, but that a combined manipulation of both peak and end did lead to significant differences in preference, even though all series had the same overall effort.
---
paper_title: Changing the default to promote influenza vaccination among health care workers

paper_content:

BACKGROUND ::: The prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure. ::: ::: ::: METHODS ::: HCWs were randomly assigned to one of two conditions. In the opt-out condition (N=61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N=61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated. ::: ::: ::: RESULTS ::: The findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated. ::: ::: ::: CONCLUSION ::: To change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.
---
paper_title: Nudges That Fail

paper_content:

Why are some nudges ineffective, or at least less effective than choice architects hope and expect? Focusing primarily on default rules, this essay emphasizes two reasons. The first involves strong antecedent preferences on the part of choosers. The second involves successful “counternudges,” which persuade people to choose in a way that confounds the efforts of choice architects. Nudges might also be ineffective, and less effective than expected, for five other reasons. (1) Some nudges produce confusion on the part of the target audience. (2) Some nudges have only short-term effects. (3) Some nudges produce “reactance” (though this appears to be rare) (4) Some nudges are based on an inaccurate (though initially plausible) understanding on the part of choice architects of what kinds of choice architecture will move people in particular contexts. (5) Some nudges produce compensating behavior, resulting in no net effect. When a nudge turns out to be insufficiently effective, choice architects have three potential responses: (1) Do nothing; (2) nudge better (or different); and (3) fortify the effects of the nudge, perhaps through counter-counternudges, perhaps through incentives, mandates, or bans.
---
paper_title: A behavior model for persuasive design

paper_content:

This paper presents a new model for understanding human behavior. In this model (FBM), behavior is a product of three factors: motivation, ability, and triggers, each of which has subcomponents. The FBM asserts that for a person to perform a target behavior, he or she must (1) be sufficiently motivated, (2) have the ability to perform the behavior, and (3) be triggered to perform the behavior. These three factors must occur at the same moment, else the behavior will not happen. The FBM is useful in analysis and design of persuasive technologies. The FBM also helps teams work together efficiently because this model gives people a shared way of thinking about behavior change.
---
paper_title: Beyond nudges : Tools of a choice architecture

paper_content:

The way a choice is presented influences what a decision-maker chooses. This paper outlines the tools available to choice architects, that is anyone who present people with choices. We divide these tools into two categories: those used in structuring the choice task and those used in describing the choice options. Tools for structuring the choice task address the idea of what to present to decision-makers, and tools for describing the choice options address the idea of how to present it. We discuss implementation issues in using choice architecture tools, including individual differences and errors in evaluation of choice outcomes. Finally, this paper presents a few applications that illustrate the positive effect choice architecture can have on real- world decisions.
---
paper_title: Nudge and the Manipulation of Choice A Framework for the Responsible Use of the Nudge Approach to Behaviour Change in Public Policy

paper_content:

In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy-makers arrange decision-making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudge based behavioural policy. Thaler and Sunstein’s own position is that the anti-nudge position is a literal non-starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti-nudge position is not a literal non-starter due to the responsibilities that accrue on policy-makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
---
paper_title: Influencing behaviour: The mindspace way

paper_content:

The ability to influence behaviour is central to many of the key policy challenges in areas such as health, finance and climate change. The usual route to behaviour change in economics and psychology has been to attempt to ‘change minds’ by influencing the way people think through information and incentives. There is, however, increasing evidence to suggest that ‘changing contexts’ by influencing the environments within which people act (in largely automatic ways) can have important effects on behaviour. We present a mnemonic, MINDSPACE, which gathers up the nine most robust effects that influence our behaviour in mostly automatic (rather than deliberate) ways. This framework is being used by policymakers as an accessible summary of the academic literature. To motivate further research and academic scrutiny, we provide some evidence of the effects in action and highlight some of the significant gaps in our knowledge.
---

Title: 23 Ways to Nudge: A Review of Technology-Mediated Nudging in Human-Computer Interaction

Section 1: Introduction
Description 1: Introduce the topic, describe the problem of sustaining user engagement in personal informatics and behavior change technologies, and state the main contributions of the paper.

Section 2: Background
Description 2: Provide a theoretical foundation by explaining dual process theories of decision-making and the concept of nudging in the context of human-computer interaction.

Section 3: Method
Description 3: Describe the systematic review process, including the identification of potentially relevant entries, eligibility criteria, search methods, data collection, and analysis procedures.

Section 4: Analysis Procedure and Dataset Description
Description 4: Offer an overview of the analysis procedure and the characteristics of the dataset, including application domains, sample sizes, study durations, and technological platforms.

Section 5: Results - Nudging Mechanisms
Description 5: Present the framework of the 23 mechanisms of nudging, clustered in six overall categories, and elaborate on how these mechanisms leverage different cognitive biases.

Section 6: Facilitate
Description 6: Explain the mechanisms that facilitate decision-making by reducing physical or mental effort, including examples like default options and suggesting alternatives.

Section 7: Confront
Description 7: Cover the mechanisms that instill doubt or create friction to prompt reflective choice by showing the consequences of certain actions and creating friction.

Section 8: Deceive
Description 8: Discuss mechanisms that use deception to affect how alternatives are perceived or how activities are experienced, including adding inferior alternatives and using placebos.

Section 9: Social Influence
Description 9: Describe mechanisms that leverage social influence, such as invoking feelings of reciprocity, raising visibility of actions, and enabling social comparisons.

Section 10: Fear
Description 10: Outline mechanisms that evoke fear to drive behavior, such as making resources scarce and reducing psychological distance.

Section 11: Reinforce
Description 11: Detail mechanisms designed to reinforce behaviors, such as just-in-time prompts and ambient feedback.

Section 12: Discussion
Description 12: Summarize the findings, address the ethical implications, discuss reasons for the failure of certain nudges, and consider factors influencing the sustainability of nudging effects over time.

Section 13: Conclusion
Description 13: Conclude by summarizing the design space of technology-mediated nudging and suggesting future research directions and potential design frameworks.