In order to explore and validate suitable methods for investigating learning processes, we are currently conducting a case study, exploring the mental models of novice students in the field of object oriented modeling and programming. After abstracting and systemizing the information that was presented to the students of our introductory CS 1 course for non-majors we have asked them to draw concept maps at four points in time. Additionally, we conducted a small midterm exam, where the students had to implement some of the most important concepts and a regular final exam. We found that learning progress can be observed in detail by evaluating the concept maps.