Influence of Professional Development on Teachers' Performance in Public Secondary Schools in Machakos County, Kenya

This study investigated the influence of professional development (PD) on teachers' performance in public secondary schools in Machakos County, Kenya. Despite numerous existing PD initiatives, persistent challenges including low teacher motivation and ineffective instructional practices necessitated a thorough examination of how specific PD components affect teacher performance. The research specifically assessed the effects of pretesting, personal development goals, learning environment, and support structures on teacher performance indicators encompassing task prioritization, timeliness, creative problem-solving, and knowledge updates. Guided by four theoretical frameworks: Adult Learning Theory, Teacher Efficacy Theory, Goal-Setting Theory, and Transformational Leadership Theory, the study employed a mixed-methods research design. Data were collected through structured questionnaires administered to a sample of 368 public secondary school teachers in Machakos County, with analysis incorporating both quantitative and qualitative techniques. The findings revealed that professional development components collectively explain 70.6% of the variance in teacher performance (R² = 0.706). Quantitative analysis demonstrated strong positive correlations, with the learning environment emerging as the strongest predictor (β =0.41), followed by leadership support (β = 0.29), personal goal setting (β = 0.25), and pretesting (β = 0.18). Qualitative findings complemented these results, highlighting teachers' recognition of pretesting as crucial for identifying training needs and emphasizing the importance of organizational support structures for effective skill application. This study provides evidence-based recommendations for systematic pretesting implementation, enhanced support structures, and improved policy frameworks for sustainable PD programs. These insights contribute significantly to optimizing teacher professional development effectiveness and ultimately enhancing educational quality in Kenyan public secondary schools, while offering a replicable model for similar educational contexts in developing regions.