I. Introduction
The use of mind maps in the classroom tends to become a widespread practice [11]. This kind of activity helps students to elaborate learning strategies like creating and organizing contents studied in class. Teachers usually consider the richness of expression given to the students as a major strength of this kind of tool. Nevertheless, this richness can easily turn into a challenge when it comes to interpret and evaluate learners' productions. As the exercises based on mind maps usually do not have a unique answer, understanding the construction processes could be very important for teachers. Moreover the understanding of these processes is often instrumental for teachers with regard to particular choices of a learner.