Web-based student evaluations of clinical faculty were collected over an 8-year period. There were 19,881 medical student evaluations over the 8-year period for all clinical clerkships, representing a total of 952 faculty. Students used a 5-point Likert scale to rate the teaching effectiveness of faculty. Criterion-based methods and standard deviation option methods were used to group faculty as "optimal" and "sub-optimal" teachers. In more than one year, 794 faculty were evaluated allowing analysis of trends in student evaluations of their teaching skills. In contrast to clinical faculty who received optimal ratings for their teaching skills, those faculty who received sub-optimal student ratings tended not to improve their teaching skills.