Though class participation and group cohesion have shown some potential to promote student performance in conventional classrooms, their efficacy has not yet been demonstrated in an online-class setting. Group cohesion, defined as member attraction to and self-identification with a group, is thought to promote positive interdependence and the success of the group's members. The current study sought to determine if group cohesion is significantly affected by the change of course setting from a live classroom to an asynchronous online-hybrid class in which students met in person only for course exams and otherwise interacted with each other through an online discussion board. Because peer interaction appears vital for the development of cohesion, we examined the relationship between participation in class discussion and students' self-reported group cohesion and exam performance. With one exception, course requirements and materials were identical between the two class sections: students in the online-hybrid course completed homework assignments, whereas students in the live section were simply encouraged to do the same. Despite the advantage conferred by mandatory homework assignments, the findings heavily favored the conventional live classroom with respect to exam performance and self-reported group cohesion. Participation in class discussion was high in both class sections. The results indicated that both student performance and group cohesion were significantly lower in the hybrid classes.