Online environments are regarded as well constructed to support collaborative and social learning. This research investigates small group collaboration and learning in the context of online exams. Incorporating constructivism and collaborative learning theories, the online Collaborative Exam features students’ active participation in various phases of the exam process through small group activities. The online Participatory Exam features similar processes except that students participate in the exam individually. A large scale field experiment was conducted to compare the two exam structures in terms of learning strategies and exam outcomes. Results show that students in the collaborative exam adopted significantly higher levels of social engagement than those in the participatory exam, learned from other students, and formed a sense of learning community. Areas for future research are briefly discussed.