RecruitingBehavioural interventionOptimizing a School-Based Therapeutic Play Intervention for Preschool StudentsThe goal of this clinical trial is to optimize a school-based therapeutic play intervention in preschool students with mild to moderate school adjustment difficulties. The aims are: 1. Determine the independent and combined effects of three intervention components (individual play, peer play, and classroom push-in sessions) on preschool children's social and emotional competence, using a factorial experimental design. 2. Use a community-engaged approach to identify and disseminate the optimized version of Primary Project for preschool implementation Researchers will compare the main and interactive effects of three components on children's social-emotional competencies. Participants will take part in a therapeutic play intervention in the school setting, and their teachers and caregivers will complete assessment instruments on children's social and emotional functioning.