DOI: 10.1145/1129006.1129017This work presents the results from a joint usability study concerning the LEGO programming environment "RoboLab". LEGO has already performed numerous evaluations on various usability aspects, aimed to enhance the overall usability and utility of the product. This study focuses on a more academic parameter; namely, the combination of different evaluation methods on the same software piece, as well as on their combined results. Therefore, two expert-based methods have been applied at the Department of Informatics of Aristotle University: a cognitive graphical walkthrough and a heuristic evaluation. The results of the study unveiled some deficiencies of the interface and some limitations of the employed methods as well.