<![CDATA[This research was motivated by the learning outcomes of Islamic Religious Education (PAI) among grade X students that had not yet reached the Learning Objective Achievement Criteria (KKTP), as a result of a learning process that remained teacher-dominated and lacked variation. This study aims to determine the extent of the effect of applying the Team Assisted Individualization (TAI) cooperative learning model on the PAI learning outcomes of grade X students at SMAN 1 Lembah Gumanti, Solok Regency.This study aims to determine the extent to which the Team Assisted Individualization learning model affects the learning outcomes of grade X students in the PAI subject. This is a quantitative study using a quasi-experimental method with a non-equivalent posttest-only control group design. The research was conducted at SMAN 1 Lembah Gumanti among grade X students in the even semester of the 2025/2026 academic year. The instrument used was a learning outcomes test consisting of 20 items. Data analysis techniques included a normality test using Kolmogorov-Smirnov, a homogeneity test, and hypothesis testing using the Independent Sample T-Test. Effect Size (Cohen's d) was then calculated to determine the magnitude of the effect of the learning model applied. The results showed an improvement in student learning outcomes after the implementation of the Team Assisted Individualization learning model at SMAN 1 Lembah Gumanti. This is evidenced by the mean posttest score of the control class at 65.57 and the experimental class at 85.00. Based on hypothesis testing, a significance value (2-tailed) of 0.000 < 0.05 was obtained, meaning H0 is rejected and Ha is accepted. The effect size analysis (Cohen's d) of 2,184 indicates that the Team Assisted Individualization learning model has a very large effect on student learning outcomes, and this research can serve as an effective alternative learning model for teachers in improving student learning outcomes.]]>
