A mail survey was conducted to study the differences among group ratings of the same instructor. A population of 72 teachers of differing background levels, teaching in the field of trade and industrial education, was selected. Each instructor was rated by one school administrator, a local supervisor, two teaching colleagues, all of the students enrolled in one of the classes of the instructor, and a self evaluation. Four different evaluation instruments were developed for the study; 15 items were common to all four instruments and these were used in the analysis. Significant differences were found in the performance rating evaluations of all four groups. Statistical data from the study is included. (DEP)