RESUMEN
Although problem-based learning (PBL) has been used for over 40 years, with many studies comparing the benefits of PBL versus other educational approaches, little attention has been paid to the effectiveness of hybrid PBL (H-PBL) curricula. Here we aimed to compare the learning outcomes of two groups of undergraduate biology students working towards a bachelor's degree: one group used an H-PBL approach, while the second used a lecture-based learning (LBL) approach. Specifically, the H-PBL group used a PBL module with interdisciplinary problems, which represented 20% of the entire curriculum. The main outcomes of evaluation were the long-term acquisition of factual knowledge and the problem-solving skills at the end of the bachelor's degree. The sample included 85 students, 39 in the H-PBL group and 46 in the LBL group. We found that an H-PBL curriculum can improve the students' learning outcomes such as long-term knowledge acquisition, problem solving skills and generic competences.