This paper investigates whether paper and video triggers stimulate different social and cognitive processes during PBL. The study focused on how medical students identified and described problems, and how they built shared cognitions that lead them to diagnose and solve problems. The results showed that students who used video triggers put more effort into communicating their understanding of the problem and relevant knowledge than students who used paper triggers. The findings contribute to discussions on how to evaluate the effectiveness of different PBL triggers in order to better integrate them into the curriculum.