The extent to which principals (n=313), supervisors (n=273), and teachers (n=313) agreed in their assessments of classroom teachers' testing proficiencies was studied in the Ohio public schools. There were 122 elementary and 191 secondary school teachers in the teacher sample. The validity of these perceptions was determined by a direct assessment of teachers' testing proficiencies or skills as demonstrated on teacher-made tests. Perceptual assessments of all three groups differed significantly. These assessments also differed from the demonstrated proficiencies of the teachers, evaluated by two judges from a sample of 175 tests made by these teachers, for a total of 6,529 test items and 455 item exercises. Lack of agreement was especially evident for teachers' test item writing and test format development skills and for the teachers' writing of items functioning at higher cognitive levels. Moderately high negative correlations were found between perceived and demonstrated proficiency assessments of teachers' test item writing skills, but moderate to high positive correlations were found between the three sets of perceptual assessments, with the highest correlation between assessments of teachers and supervisors. Teachers rated their testing proficiencies higher than did principals, and principals rated proficiencies higher than did supervisors. Results suggest that perceptions of educational staff may not be accurate guides for determining needs for inservice training. Both preservice and inservice teacher educators need to increase attention to test item writing skills and the writing of items that measure beyond simple knowledge levels. Seven tables present survey and assessment data. (SLD)