Methodological explanations for the modest effects of feedback from student ratings.

A recently completed review and statistical integration of the quantitative research on the feedback college teachers get from student ratings yielded an overall effect size of 342. This indicates a persistent positive effect for feedback, but this small difference has modest practical significance. Why has this intuitively appealing approach to instructional improvement been so unimpressive in empirical tests? Using Cook and Campbell's (1979) threats-to-validity framework, we examine methodological and conceptual issues in the areas of internal validity, statistical conclusion validity, external validity, and construct validity