A Reliability Generalization Study of the Teacher Efficacy Scale and Related Instruments

Teacher efficacy has proven to be an important variable in teacher effectiveness. It is consistently related to positive teaching behaviors and student outcomes. However, the measurement of this construct is the subject of current debate, which includes critical examination of predominant instruments used to assess teacher efficacy. The present study extends this critical evaluation and examines sources of measurement error variance in the Teacher Efficacy Scale (TES), historically the most frequently used instrument in the area. Reliability generalization was used to characterize the typical score reliability for the TES and potential sources of measurement error variance across studies. Other related instruments were also examined as regards measurement integrity.