Informatics in Education

We have researched how the Java PathFinder software model checker can be adopted to the specific needs of test data generation in automatic assessment. Practical problems considered are: how to derive test data directly from students' programs (i.e., without annotation) and how to visualize and how to abstract test data automatically for students? Interesting outcomes of our research are that with minor refinements generalized symbolic execution with lazy initialization (a test data generation algorithm implemented in PathFinder) can be used to construct test data directly from students' programs without annotation, and that intermediate results of the same algorithm can be used to provide novel visualizations of the test data.