Non-Naïve Participants Can Reduce Effect Sizes

Jesse Chandler, University of Michigan, USA
Gabriele Paolacci, Erasmus University Rotterdam, The Netherlands
Eyal Peer, Bar-Ilan University, Israel
Pam Mueller, Princeton University, USA
Kate Ratliff, University of Florida, USA
Although researchers often assume their participants are naïve to experimental materials, this is not always the case. We investigated how results in a set of two-condition experiments depended on whether participants completed them once already. Non-naivety markedly decreased effect sizes, especially when participants were assigned to a different condition.
[ to cite ]:
Jesse Chandler, Gabriele Paolacci, Eyal Peer, Pam Mueller, and Kate Ratliff (2015) ,"Non-Naïve Participants Can Reduce Effect Sizes", in NA - Advances in Consumer Research Volume 43, eds. Kristin Diehl and Carolyn Yoon, Duluth, MN : Association for Consumer Research, Pages: 18-22.