In recent years, universities have been increasingly complaining that the basic mathematics skills of new students barely satisfy the requirements of many degree courses. They criticise the high dropout rates, especially in mathematics and natural sciences degrees, and link them to the lack of basic skills of university entrants. Many universities are reacting to this problem by setting up or reorganising preparatory courses in subjects with mathematical content. School knowledge in mathematics is usually repeated in these preparatory courses. The orientation of these preparatory courses is, however, very heterogeneous and ranges from the teaching of skills to development of general competences. The type of preparatory course (e-learning or classroom based course) also varies. The effect of such preparatory courses is being examined at many universities via preliminary tests and follow-up tests. Using Kassel University as an example, we are examining the possible correlations between the examination results in maths, attendance of a preparatory course and the test results at the start of the course. We are also looking at whether correlations between the type of preparatory course, classroom-based or e-learning, and the exam results can be established. We are also interested in whether it is possible to predict the course progress with the help of a test at the start of the course. The article shows the possibilities and the limits in deriving information from data on test and exam results. This could be an interesting perspective for many universities.