This study was undertaken to assess the accuracy of principals' judgments of the effectiveness of the teachers they supervise. Each of 46 principals was asked to fill out a brief form judging the overall effectiveness of each of the teachers in his or her school. The form asked how effective the teacher was in performing three roles: (1) promoting…

This paper assesses the credibility of a single total instrument score and various logical sub-scores derived from a series of summative judgments about the quality of teaching performance. The objectives were to compare the generalizability of alternative Teacher Performance Assessment Instrument (TPAI) scores, to compare the dependability of…