




Does that statement seem a little crazy? Perhaps, but I think it is true. Humans are highly adaptive and quite capable of molding themselves and their behavior to their environment and the tools thy use. We need only look at the evolutionary dominance humans have achieved to see this is true. Yet when looking at humans (and other animals) as behaving systems, Herbert Simon discovered that the internal peculiarities of the behaving system, the human or animal, has minimal impact on the way the behaving system (the human) interacts with the larger system of the environment. Rather, “complex behavior is largely a reflection of a complex environment.”


What this separation means on an abstract level is that there is what amounts to a conceptual interface layer between the human (or user) and their environment or tool (the application). You’ve probably guessed by now that Simon’s rather esoteric, but very worthwhile discussion of the nature of human behavior can inform our approach to interaction design, mainly because of that interface layer. The benefit of this understanding of human behavior is that the reverse is also true. The internal behavior of an environment or tool does not have to dictate the interaction behavior with the user.


This independency of the interface layer is essential for interaction design practice because it enables the creation of truly excellent experiences for user interfaces. Instead of designing system behavior to reflect the internal complexity of the tool, application, or program, we can design system behavior to support user understanding and decision-making. This is important because users don’t care how complex a system is or even what the internal information flow looks like. Since behavior is not necessarily dependent on internal complexity, we can, to a certain extent, treat the user and the application as black boxes with an interface layer between them by focusing on the outputs of each. The user’s outputs would be their goals and the system’s output would be the accomplishment of those goals. The user experience design should address how the system can support the user in achieving those goals.


Naturally, demographics and other differences in users still need to be addressed so it will not be a completely opaque black box, but these metrics will determine interaction strategies beyond a basic level of intuitiveness, a sort of minimum usability level. Because we can expect users to adapt to the system, if they fail to do so, we should look to the system for failures rather than the user. By understanding the relationship between users, systems, their internal and external behaviors and the interface between them, designers can better support users in utilizing systems to achieve their goals. Failure to understand how these internal and external behaviors interact with each other on both the user and system level leads to the inability to create an appropriate interface layer. The phrase ‘user error’ ignores the adaptability of humans. Considering how capable we humans are at adapting, if we fail to do so, that points to an overly complex system interface rather than deficiencies in the human (user).


What do you think about internal and external behaviors affecting relationships between systems and users?