
The study of the subjects' conceptions and beliefs should be approached through various and indirect methods, because of their unconscious level. In this paper we describe the use of the commentary of a text' to characterize the prospective teachers' conceptions and beliefs on mathematics, its teaching and learning, as well as their evolution after some teaching practices. The data analysis methodology, which could be useful to other educational investigations, combines qualitative analysis with statistical methods to determine the structure of the data tables obtained. More precisely, correspondence analysis and log-linear analysis, allow us visualizing the original structure of the text, comparing it with the structure of the students' commentaries, and studying its individual and overall evolution.