Reported is a study of the effect of selected modes of feedback on teacher behavior in a microteaching situation. Forty students enrolled in an elementary school science methods course participated in this study. Four groups were randomly organized into three treatment groups and one control group. One treatment group received verbal feedback from a trained observer. The second group received videotaped replays of their presentations. The third treatment group received both feedback modes. Four fifteen-minute microteaching sessions were scheduled at two-week intervals. Verbal feedback was supplied in terms of the Classroom Observational Record (COR). The taped lessons were encoded using the COR. Thirteen of the twenty-three categories identified were selected for analysis. The Kruskal-Wallis Analysis of Variance by Ranks was used to determine if one or more of the modes had a significantly different effect on teaching behaviors. The Mann-Whitney U Test was used to identify any group(s) that differed. No differential behavior modification occurred as a function of type of feedback provided. It was also inferred from data obtained on the Measurement of Science Process that the mode of feedback had no differential effect on the subjects' ability to use the processes of science. The mode of feedback seemed to have no differential effect on the subjects' attitude toward various aspects of teaching situations. (Author/EB)