This study examined impact of a staff development program on increasing the accuracy of teachers' self-evaluation of classroom performance. Teachers were provided with specific formal feedback through a program called The Effective Use of Time Program (EUOT). The program had four components: (1) observation in the classroom and feedback about performance; (2) information from research applied in the context of a teacher's specific situation; (3) opportunities for guided practice; and (4) observation and feedback following workshops to assess improvement. To test EUOT, data from 40 elementary, junior high, and secondary teachers were examined. These observations, using the Stallings Observation Instrument (SOI), provided a message of actual teacher performance. Four variables were selected for comparision from self-rating and observation data: (1) managerial and organization efficiency; (2) student discipline; (3) interactive instruction; and (4) monitoring. Results showed that teachers improved their actual performance and gave themselves higher ratings at the end of the program. In general, teachers were no more accurate in assessing their performance after training, although junior high teachers showed significant relationships between posttraining self-ratings and observed behavior. Several explanations are given for failure of data to show wider improvements in accuracy of self-assessment, and five tables are included to show results. (LMO)