Computer Aided Modelling Exercises

This paper present experiences with the use of a didactical CASE-tool for teaching object-oriented domain modelling. The tool provides the student with interactive feedback and verification of the models helping in this way to find obvious mistakes. Furthermore, the tool enables validating the model against user requirements by generating a prototype. This helps the student in building a mental model of a concrete information system build from the conceptual model. The tool is positively evaluated by the students and was shown to have a positive impact on the student’s capabilities for object-oriented modelling. 1. Setting the stage 1.1. Educational mission This paper presents experiences with a didactical special-purpose CASE-tool in the context of teaching object-oriented business modelling. The main goal of the course is to familiarise students with objectoriented analysis techniques and to let them acquire the necessary skills to actually perform business modelling. In addition, students should be able to envisage the mutual relationship and influence between the IT-system and the organisational work system. For example, the student should learn to evaluate the implications of differences between models both from an IT and an organisational perspective. Obviously, given the goals of the course, a lot of exercises are needed to acquire the necessary skills. Exercises start with a textual description of some user requirements, which should be interpreted by the student and transformed into an object-oriented business model. Given the fact that such user requirements can be interpreted in different ways (because of their informal aspect), students should receive individual feedback on their solution. Additionally, a detailed comparison of their solution with a model-solution and alternative solutions of other students helps to gain insight in the consequences and implications of particular modelling choices. The student’s capability is a crucial element to achieve the educational goal. The course is attended by a set of students with a large variation in preliminary knowledge of object-oriented concepts and programming skills. One can roughly identify three major groups of students. One group of students are very much technology oriented and have good object-oriented programming skills. Their ITorientation is sometimes a disadvantage as it hampers them in taking a more business oriented view towards specifications: they tend to think in a solution-oriented mode, while the goal of the course is to focus on the characteristics of the problem world. The second group of students have a substantial set of business-oriented skills, are skilled in data modelling and have basic skills in object-oriented programming. This is the group of students that is most at ease with the presented material. However, because of their preliminary database course, these students tend to think in a purely data-oriented way, and have difficulties in conceptualising the behavioural aspects of an object-oriented model as defined in class operations and finite state machines (FSM). Finally, for a third group of students, this course is their first contact with object-orientation. They have no programming skills and have not yet followed a course on database modelling. Especially this group has difficulties of imagining the concrete system that will result out of an abstract model. 1 The course’s page can be found on http://mermaid.econ.kuleuven.be/content.aspx/