Assessment of Mastery Learning Approach in Improving Students Achievement in Cosmetology in Osun State

This study assesses the effectiveness of the mastery learning approach in improving student achievement in cosmetology in vocational institutions in Osun State, South West Nigeria. Cosmetology is one of the fastest-growing vocational trade areas in Nigeria, driven by expanding beauty and personal care markets. Despite high enrolment in cosmetology programmes, many graduates lack industry-standard competencies in areas such as hair treatment, skin care, and nail technology. Mastery learning, which requires students to demonstrate prescribed competence levels before advancing to new content, offers a structured approach to closing learning gaps. A quasi-experimental design is employed, with 80 cosmetology students divided into experimental and control groups across two vocational training institutes in Osogbo, Ilesa, and Ede local government areas. The experimental group follows mastery learning cycles, while the control group receives conventional instruction. A validated performance assessment rubric measures cosmetology competencies at pre-test and post-test intervals. Analysis of covariance is used. The study predicts significantly higher achievement for the mastery learning group. Recommendations include teacher training on mastery learning implementation, formative assessment scheduling within cosmetology programmes, and provision of standard salon equipment in training facilities. This study adds to instructional methods research in beauty and cosmetology vocational education in South West Nigeria and provides a replicable model for improving practical outcomes in similar programmes. Keywords: mastery learning, cosmetology, student achievement, Osun State, vocational education