Background:
There is a growing interest in the concepts of teacher-focused versus student-focused approach to teaching. The student-focused approach is more concerned with assisting student understanding and conceptual change rather than the transmission of content to students. Problem-based learning (PBL) is an exciting alternative to traditional classroom learning and provides the opportunity of moving from a teacher-focused to a student-focused teaching environment. Traditionally PBL is thought to be resource intensive and only suitable for small group of students who work closely together with access to regular tutorial sessions. In this study, without any changes in the level of usual resources (e.g. number of tutors), we have tried to use a PBL oriented approach for teaching a large group of students.

Methods:
The study group were students (n= 188) taking the practical class for a second year Immunobiology module in the School of Biology. Before the practical the students were exposed to two 30 minute PBL-orientated sessions. In the first session some general problems relating to the practical subject were posed, and students were asked to research these independently. The second session centred around a discussion of their findings. The objective was to encourage independent thought processes and increase the depth of background understanding before the practical. Students took the practical class1-2 weeks after the second PBL-orientated session and were provided with questionnaires to assess their perception of the tutorial sessions.

Results:
The questionnaires showed that students were generally positive about the PBL sessions. A clear majority (ca. 60%) recommended PBL to be used in the future and gave a positive overall rating, however, a quarter of the students did not appreciate PBL and would not recommend it for the future. The recommendation for the use of PBL in the future was strongly related to how enjoyable student found the preparation for the practical but also to how difficult it was to find information for independent background study. Indeed, the main improvement the students pointed out was the need for more guidance on PBL way of learning. Students found that PBL helped with their understanding (ca .70 %) of the practical which was also identified as the main positive feature of the PBL sessions.

Discussion:
Observing students during the introductory PBL sessions suggested a lack of engagement and reluctance to participate by some students. To improve this, one potential future avenue would be a “fish bowl” approach, where a small number of students are randomly selected to present material.

The outcome of this study shows that PBL doesn’t have to be resource intensive and still be positively received by the students. The lack of recourses can be compensated for by preparation. Indeed, the lecturer’s reflection suggests that preparing the students with clear guidance and the lecturer with techniques for better interacting with large groups are essential.