To substantiate the theoretical efficacy of microteaching with videotaped feedback, 25 student teachers were assigned to a Teaching Techniques Laboratory in which microteaching methods were emphasized. Following completion of the training program, participants and a control group with no laboratory experience received placement in Chicago area schools. Videotapes of two instructional sessions were obtained for each of the 50 student teachers. Differences between experimental groups on an application of Flanders' Interaction Analysis Technique to the videotaped sessions and judgments of competence attainment by cooperating senior-teachers were not significant. However, analyses of variance indicated highly significant differences on both the TPAS (Teacher Performance Appraisal Scale) and ITEQ (Illinois Teacher Evaluation Questionnaire), favoring laboratory participants. The findings are considered to demonstrate the effectiveness of microteaching experiences in sensitizing teachers to a range of pupil behavioral cues, verbal and non-verbal, and the essential feedback on interest and understanding of lesson materials they represent. (SS)