In order to develop computer competence, users need to understand principles of its operation in addition to memorizing where a particular operation is located in menus. Understanding a principle ease transfer of learning, hence the understanding helps learning a new application. These principles, e.g. functional dependency, are based in computer science, and are thereby precise and general. Two cycles of the Action-Process-Model (Aharoni, 2000) of learning abstract concepts are used to characterize the learning process of such principles. Observations and tests of students in a high school show discrimination errors and forgetting already in the first of six stages of learning. Nevertheless, the majority of the students arrived at the fourth stage of learning functional dependency. In order to improve learning, teachers need to provide both intermediate and general concepts so that the learners can verbalize their actions and hence improve their understanding.