This study aims to examine the effects of Project-Based Learning (PBL) on student proactive behavior, collaboration skills, and environmental engagement, with a focus on the moderating role of social skills. Using path analysis and multilevel regression analysis, data were collected from students in Indonesia to test eight hypotheses regarding the relationships between PBL, student behaviors, and environmental engagement. The results indicate that PBL positively influences proactive behavior and collaboration skills, which in turn significantly impact environmental engagement. Social skills were found to moderate the effects of PBL on proactive behavior and collaboration skills, but did not significantly moderate the relationship between student behaviors and environmental engagement. Key findings suggest that PBL, combined with strong social skills, enhances students' proactive and collaborative tendencies, but other factors may influence their environmental engagement. The study contributes to sustainability education literature by highlighting the role of social skills in enhancing PBL's effectiveness and suggesting that individual and contextual factors beyond social skills might play a role in fostering environmental commitment. Limitations include reliance on self-reported data and the focus on an Indonesian context, which may limit generalizability. This study offers novel insights by integrating PBL with social skills in sustainability education and recommends future research explore additional moderating factors to provide a more comprehensive understanding of student engagement. • PBL enhances students' proactive behavior and collaboration skills. • Proactive and collaborative skills boost environmental engagement. • Social skills strengthen PBL effects on proactive behavior. • Social skills strengthen PBL effects on collaboration skills. • Other factors may shape students' environmental engagement.
Sukidin et al. (Sat,) studied this question.