When Role Playing Doesn’t Work: Seven Guidelines for Grounding Usability Testing in Participants’ Real Lives
http://www.uxmatters.com/MT/archives/000317.php

Peyrichoux, Isabelle
UXmatters
2008

Abstract:

Usability testing makes use of a lot of role-playing scenarios like this one, and many findings and design recommendations result from participants’ responses to these scenarios. But an over-reliance on role playing when testing a product and making design recommendations can have major downsides and risks