The user interface (UI) is a key component of an interactive software application; therefore, it is important to provide software developers with basic UI design skills. However, teaching UI design is challenging, even at a basic level, and there is little teaching support. In this article, we investigate the benefits of the feedback-enriched simulation environment (FENIkS) for learning fundamental UI design principles toward designing the functional aspects of a UI. FENIkS is a model-driven educational environment making use of simulation as learning support by generating a UI and the underlying application starting from conceptual domain and presentation models. The generated application and UI contain feedback elements for the learners. This feedback shows if the generated prototype is compliant with certain key design principles and why the principles are considered to be well applied or not. We conducted an experiment using bachelor-level courses to observe the effects of FENIkS on the learning of UI design principles by novice UI designers. The effectiveness of FENIkS was measured by comparing the results of students on a test performed without and with the use of FENIkS, using statistical methods. The findings show an improvement in student's learning of UI design principles when using the FENIkS approach.