Recent calls have been made for a fundamental reorientation in higher education from a curriculum that simply transmits information (learner as receiver) to one that encourages students actively to construct their own knowledge and practice using new skills and concepts (learner as constructor). In response, the Case Analysis in Organisational Situations (CAOS) assessment tool was developed for use in teaching organisational behaviour. It follows the principles of problem‐based learning and group work, using an unfolding case design. A pre‐test (n=365), immediate post‐test (n=323) and delayed post‐test (n=129) design was implemented to evaluate the effectiveness of this new learning tool. The assessment of student approaches to learning revealed that students were more likely to adopt a deep approach to learning at the end of CAOS than at the beginning. In general, the results show that CAOS is a useful web‐based tool that promotes learning in organisational behaviour. The benefits of CAOS and some suggested improvements to the existing CAOS format are discussed.