Field supervisors' assessments of trainee performance: Are they reliable and valid?

This study draws attention to the very real possibility that supervisors' assessments are not as reliable or valid as professional psychology assumes. The study examines end-placement reports accrued over a 12-year period from 130 supervisors who rated performance in 291 field placements completed by 131 clinical psychology trainees. It is likely that supervisor ratings are affected by a leniency bias. Further, earlier placement ratings are poor predictors of subsequent placement ratings by different supervisors. Ratings on the 11 broad performance dimensions yield a single clinical skills factor within which items congregated into two clusters: Assessment and Intervention; and Interpersonal and Professional skills. Factors that contribute to supervisor bias and strategies to reduce bias and to enhance the value of supervisor ratings are discussed.