Implementation of STAD-type Cooperative Learning to Improve Vocational High School Students Milling Practice Learning Outcomes

Abstract

This classroom action research examined the use of Student Teams Achievement Division (STAD) to improve milling practice learning outcomes among 24 Grade XI machining students at SMK Negeri 1 Sumatera Barat. The study was conducted in two cycles using the Kemmis and McTaggart stages of planning, action, observation, and reflection. Data were collected through cognitive tests, a milling performance rubric, group-performance observation, student-activity observation, and documentation. The results showed consistent improvement after the learning groups were formed heterogeneously, individual responsibilities were clarified, teacher guidance was intensified, and group recognition was provided. The mean cognitive score increased from 64.67 in the pre-cycle to 84.58 in Cycle II, while mastery increased from 25.00% to 91.67%. The mean practical score rose from 72.25 in Cycle I to 82.04 in Cycle II, with mastery increasing from 41.67% to 87.50%. Group performance improved from 76.00 to 86.40, and student activity increased from 69.58 to 81.79. These findings indicate that STAD strengthens peer support, individual accountability, cooperation, and active engagement, thereby improving both theoretical understanding and practical milling skills. STAD is therefore suitable as an alternative instructional model for vocational machining practice.