This study concerns the confirmatory factorial analysis test of the correspondence between a theory of the definition of the interests proposed in a list of factors and the responses from 5304 subjects in two self-evaluation questionnaires. The questionnaires were provided by a professional advice and support IT tool, Inforizon. It allows the user to explore professional worlds, according to his particular interests. The principles at work are designed to overcome difficulties regularly encountered in the use of interest scores. The empirical structure of the responses to the questionnaires appears to be compatible with the definition model. A second stage is the exploratory research of the explanatory and parsimonious dimensions of the approximately circular organisation of the interest factors.