Validating the Teacher Effectiveness Scale: A Psychometric Analysis of Its Validity and Reliability

This study validated the Teacher Effectiveness Scale (TES) by analyzing its psychometric qualities using Item Response Theory (IRT) and Classical Test Theory (CTT). The TES assesses six components of teacher effectiveness: teacher personality, classroom organization and management, lesson planning, lesson implementation, student progress monitoring, and professional development. A cross-sectional survey design was employed across Oyo, Osun, and Ondo States in Nigeria. In the pilot phase, 40 teachers from four junior secondary schools in Oyo State participated. The second phase, which focused on construct validation, involved 320 senior secondary school teachers from 16 public and private schools in Osun State, using stratified sampling. In the final phase, 240 teachers from 16 schools in Ondo State were assessed for consistency and applicability. Confirmatory full-information factor analysis confirmed the TES’s structural validity with strong factor loadings (0.58–0.84). Convergent and discriminant validity were established for five factors, but Factor 6 was eliminated. IRT reliability analysis showed internal consistency (0.7–0.9). The revised TES, with 32 items across five factors, is a valid and reliable instrument for assessing teacher effectiveness. Future research should examine its predictive validity regarding student learning outcomes and its application across different educational contexts.