Research on social responses to computers often assesses only first-impression reactions during a single experimental session, providing limited knowledge about the lasting effect of the results. In this work, we assess the lasting strength of social desirability bias effects on an interface designed to track exercise, manipulated to have high or low personalization (text vs. anthropomorphic conversational character). After 40 days of daily interactions by 25 participants, we found that self-reported exercise was more accurate when reported to the character vs. text. We also find that, for both conditions, participants' decision to initiate a session is greater when they have done more exercise. Moreover, we show that this effect significantly increases over time for participants in the character condition, and decreases for participants in the text condition. This study demonstrates that Media Equation effects can grow stronger or weaker over time, depending upon the presentatio...
Laura M. Pfeifer, Timothy W. Bickmore