Content area
This study examines the understanding of various aspects relating to the concept of interface class by Management Information Systems students. The examined aspects were: definition, implementation, class hierarchy and polymorphism. The main contributions of this paper are as follows: we developed a questionnaire addressing the above aspects; we classified and analysed the students' responses to determine the students' understanding of the above aspects and to highlight common faulty solutions. The results obtained reveal that majority of the students demonstrated understanding of definition and implementation of interface class, however, only two- thirds of the students demonstrated understanding of interface class in the context of class hierarchy and only one third of them demonstrated understanding of polymorphism in the context of interface class. The students' utterances from the interviews shed light on their difficulties.