How effective is a notation in conveying the writer’s intent correctly? This paper identifies understandability of design notations as an important aspect which calls for an experimental comparison. We compare the success of university students in interpreting business process descriptions, for an established graphical notation (BPMN) and for an alternative textual notation (based on written use-cases). Because a design must be read by diverse communities, including technically trained professionals such as developers and business analysts, as well as end-users and stakeholders from a wider business setting, we used different types of participants in our experiment. Specifically, we included those who had formal training in process description, and others who had not. Our experiments showed significant increases by both groups in their understanding of the process from reading the textual model. This was not so for the graphical model, where only the trained readers showed significant increases. This finding points at the value of educating readers of graphical descriptions in that particular notation when they become exposed to such models in their daily work.