The Influence of Principals’ Instructional Leadership, Work Discipline, and Self-Concept on Vocational High Schools Teachers’ Professional Competence

This study aims to analyze the effects of (1) school principals' instructional leadership, (2) work discipline, and (3) self-concept on teachers' professional competence in vocational high schools in Tembilahan District, as well as (4) their combined influence. Employing a quantitative approach with an ex post facto and correlational design, data were collected through validated and reliable questionnaires (Pearson and Cronbach’s Alpha). A proportional random sampling technique was used to select 156 teachers. Multiple linear regression analysis revealed that all three variables significantly impact teachers' professional competence, both individually and collectively, contributing 54.4% to its variance. The findings emphasize the need for optimizing instructional leadership, enhancing work discipline, and fostering self-concept to improve teachers' professional competence.