RateMyProfessors.com offers biased evaluations
Legg, Angela M., and Janie H. Wilson. 2012. “RateMyProfessors.com Offers Biased Evaluations.” Assessment & Evaluation in Higher Education 37 (1): 89–97. doi:10.1080/02602938.2010.507299.
Article used RMP questions in in-class surveys and then collected RMP results posted after the surveys were done. Found that the measures were different for the same questions in the two media,