Higher professional education aims to prepare graduates for the complexity of professional practices. The development of conceptual understanding is important to deal adequately with this complexity, especially in an unstructured professional domain such as international business. The aim of this dissertation is to investigate the concept conceptual understanding in this professional domain, how it can be measured, what it looks like, how it changes, and in what ways it differs between students. The dissertation comprises five empirical studies for which data collection took place at a university of applied sciences in the Netherlands.