In assessment of problem solving the use of short case-based testing is a promising development. In this approach an examination consists of large numbers of short cases each of which contain a small number of questions. These questions are aimed at essential decisions.Writing such cases, however, is not easy. In this article a description of this type of examination is provided.Also strategies and pitfalls are described in writing these cases. These strategies pertain to the selection of essential decisions, the careful writing of cases and questions and the selection of question formats.