Persuasive Technology Lab captology.stanford.edu Background for P-I Theory To understand Prominence-Interpretation Theory . . . Think back on the two types of studies: 1. Stanford Web Credibility Surveys – 1999, 2002 2. Stanford MostCredible Study – 2002 Both studies examined credibility, but they asked study participants to do different things. #50 Prepared for Luke Wroblewski ©2003, BJ Fogg. Commercial use not allowed.