Principal-Led In-Service Training and Teacher Job Performance in Public Junior Schools in Nyahururu Sub-County, Laikipia County, Kenya

This study examined the relationship between principal-led in-service training and teacher job performance in public junior schools in Nyahururu Sub-County, Laikipia County, Kenya. The guiding research question was: How do principal-led in-service training programs influence teacher job performance in public junior schools in Nyahururu Sub-County, Laikipia County, Kenya? The study was anchored on Transformational Leadership Theory and complemented by Instructional Leadership Theory and Adult Learning Theory (Andragogy). A convergent parallel mixed-methods design was employed. The target population comprised 482 Teachers Service Commission (TSC)-deployed teachers and 28 school principals in 28 public junior schools. Stratified random sampling yielded 219 teachers, while 15 principals were purposively selected for interviews. Data were collected using teacher questionnaires and interview guides for principals, with documentary evidence used to support triangulation. Quantitative data from 190 teachers were analyzed using descriptive statistics and inferential statistics, while qualitative data from 15 principals were analyzed thematically. Teachers reported a positive perception of principal-led in-service training (M = 3.76, SD = 0.92). The strongest-rated aspects concerned overall instructional performance (M = 3.88, SD = 1.09) and lesson preparation and planning (M = 3.86, SD = 1.10). The one-way Analysis of Variance (ANOVA) revealed a statistically significant difference in teacher job performance across varying levels of in-service training participation (F(2, 187) = 12.65, p < 0.001).The corresponding shared variance was approximately 40.7%. Qualitative findings indicated that principals organized CBC orientation, refresher courses, instructional methodology training, and assessment-focused training, with emphasis on curriculum alignment, practical application, and follow-up support. Funding constraints, teacher workload, and limited time emerged as major implementation challenges. The findings suggest that principal-led in-service training is associated with teacher job performance, particularly when training is relevant to classroom needs and accompanied by follow-up, observation, feedback, and adequate time and resources. The study recommends strengthening school-level instructional leadership capacity, protected time for professional learning, needs-based training, and systematic post-training support.