The underlying aim of the work related in this paper, was to define Design Patterns for recording and analyzing usage in learning systems. The implied "bottom- up" approach when defining a Design Pattern brought us to examine data collected in our learning system through different lights: (1) the data type, (2) the human roles involved in the production of the data, or interested by their uses, and (3) the nature of the data analysis. This method has allowed us to have a global view on the data, which can be easily generalized and formalized.