Abstract
<title>Abstract</title> <p>Background Active learning has become a central paradigm in undergraduate science, technology, engineering, and mathematics (STEM) education, yet the magnitude and consistency of its effects on student achievement, engagement, and equity remain unclear. Objective This systematic review synthesizes empirical evidence on the effectiveness of active learning strategies in undergraduate STEM courses, focusing on cognitive (achievement, conceptual understanding), affective (motivation, self-efficacy), and equity-related outcomes (performance gaps, inclusion). Methods In accordance with PRISMA guidelines, we searched Scopus, Web of Science, ERIC, and PsycINFO for peer-reviewed empirical studies published between 2000 and 2025. Eligible studies implemented a clearly defined active learning intervention, used a comparison condition, and reported quantitative outcomes. Owing to heterogeneity, we conducted a narrative synthesis with vote counting. Results Seventy-two studies met inclusion criteria. Active learning strategies were associated with improved course grades or exam scores in 79% of comparisons, enhanced conceptual understanding in 74%, and increased engagement or motivation in 68%. Equity-focused analyses indicated that active learning often reduced performance gaps, though effects varied with implementation fidelity and classroom climate. Conclusions Active learning strategies generally positively affect achievement, conceptual understanding, and engagement, with context-dependent equity benefits. Future research should prioritize rigorous experimental designs, transparent reporting, and systematic attention to equity.</p>