Comparing How a Chatbot References User Utterances from Previous
  Chatting Sessions: An Investigation of Users' Privacy Concerns and
  Perceptions
Samuel Rhys Cox Yi-Chieh Lee Wei Tsang Ooi
Chatbots are capable of remembering and referencing previous conversations,
but does this enhance user engagement or infringe on privacy? To explore this
trade-off, we investigated the format of how a chatbot references previous
conversations with a user and its effects on a user's perceptions and privacy
concerns. In a three-week longitudinal between-subjects study, 169 participants
talked about their dental flossing habits to a chatbot that either, (1-None):
did not explicitly reference previous user utterances, (2-Verbatim): referenced
previous utterances verbatim, or (3-Paraphrase): used paraphrases to reference
previous utterances. Participants perceived Verbatim and Paraphrase chatbots as
more intelligent and engaging. However, the Verbatim chatbot also raised
privacy concerns with participants. To gain insights as to why people prefer
certain conditions or had privacy concerns, we conducted semi-structured
interviews with 15 participants. We discuss implications from our findings that
can help designers choose an appropriate format to reference previous user
utterances and inform in the design of longitudinal dialogue scripting.