Process modelling has over the years become an essential skill in Information Systems and Business Process Management practice. Consequently, more and more training programs have evolved, teaching different process modelling languages. Two popular process modelling languages are being compared in this experimental study. Experiment participants received extensive training in one language but not the other, leading to the expectation that learning outcomes would be better in the case of the familiar language. Our study provides empirical evidence that this is not the case. In fact, it is shown that participants achieved similar learning outcomes when confronted with the unfamiliar language. Our results lead to a fundamental question, namely whether it is actually an important teaching decision what sort of process modelling language is being taught. Our findings suggest that education and research in process modelling should focus on aspects other than the style, nature or features of languages and tools.