At the beginning of the user study, the test persons were put into a typical public transport situation by means of a virtual train ride in the SmartMMI demonstrator. For this purpose, the test persons were given predefined tasks which had to be completed in the shortest possible time using SmartWindow. Subsequently, the study participants were given laminated icons which had to be grouped into one of the five categories and ranked according to their comprehensibility. Finally, the test persons filled out an online questionnaire, in which some personal information such as demographic information as well as information on the affinity for technology and public transport was asked anonymously.