A study examined the effects on teacher performance and attitudes of several manipulations of the conditions under which the microteaching supervisor provides feedback: he bases his critique on (1) a videotape of the microteaching lesson which he views with the microteaching teacher (VT group); (2) an audiotape instead (AT group); (3) his experience with the live lesson (LL group); or (4) the responses of the microteaching student to the Stanford Teacher Competence Appraisal Guide (STCAG)(SR group). All students in a basic educational psychology course (N=37) were randomly assigned to eight groups, two groups randomly assigned to each treatment. Data was obtained from STCAG scores and an attitude scale measuring attitudes toward various aspects of the microteaching experience. Analyses of covariance indicated significant differences in students' ratings of the performance of subjects within the four treatments on all 13 variables. Major findings: The AT treatment appears to be the strongest, resulting in the greatest amount of change as measured by student ratings and also being highly valued by the microteaching teachers. The SR treatment effectively produced change in teacher performance but was not highly valued. The VT treatment appeared relatively weak in producing change yet was highly valued. The LL treatment appears least effective and tends to be lowly valued. (JS)