Hypotheses
Three hypotheses were developed that predict the effect of matching the personality of the robot—expressed through
gaze—to the personality of users, as well as the potential effect of users’ intrinsic motivation.
Hypothesis 1—Matching the robot’s personality to the user’s personality will improve the user’s subjective ratings of the robot’s performance.
This hypothesis follows from similarity-attraction theory, which predicts that a person will be more attracted to others
who match their personality than to those whose personalities do not match [22]. Thus, we predict a strong interaction effect
between user personality and robot personality.
Hypothesis 2—Matching the robot’s personality to the user’s personality will improve compliance with the robot’s requests to engage in the task for a longer period of time.
This hypothesis also predicts a strong interaction effect between user personality and robot personality and follows from
similarity-attraction theory. Previous work in socially assistive robots found a similar interaction effect on compliance
between user personality (extrovert or introvert) and robot therapy style (challenging or nurturing) [44]. Our own data
collection, which we presented earlier, also lends some preliminary support for this hypothesis, as the two personalitymatching
dyads participated in the puzzle task longer than both personality-mismatching dyads.
Hypothesis 3—The user’s intrinsic motivation for the task will interact with the personality-matching effect on compliance.
Users with low intrinsic motivation will be more affected by personality-matching than users with high intrinsic motivation.
If a user has high intrinsic motivation for the puzzle-solving task, they would inherently find the task interesting or enjoyable
and thus would not respond to external motivation attempts from a socially assistive robot [38].