The Dynamic Effect of Source Certainty on Consumer Involvement and Persuasion

Uma Karmarkar, Stanford University, USA
Zakary Tormala, Stanford University, USA
This research explores the effect of source certainty—that is, the level of certainty expressed by a message source—on persuasion. We propose an incongruity hypothesis, suggesting that source certainty effects depend on source expertise. In three experiments, consumers receive recommendations (e.g., a restaurant review) from sources of varying expertise and certainty. Across experiments, low expertise sources are more persuasive when they express certainty, whereas high expertise sources are more persuasive when they express uncertainty. Moreover, these effects are mediated by involvement. Thus, low (high) expertise sources can gain interest and influence by expressing certainty (uncertainty).
[ to cite ]:
Uma Karmarkar and Zakary Tormala (2010) ,"The Dynamic Effect of Source Certainty on Consumer Involvement and Persuasion", in NA - Advances in Consumer Research Volume 37, eds. Margaret C. Campbell, Jeff Inman, and Rik Pieters, Duluth, MN : Association for Consumer Research, Pages: 126-129 .