In this article, the question of the performance of the interview of explicitation of Pierre Vermersch for the analysis of the competences is put by leaning on the educational experiment of realization of portfolios of competences made by the students of DUT (two-year technical degree). The interview of explicitation is a technique of help to the verbalization a posteriori of an activity / task realized by a person, both at the level of the actions material and mental. The concept of action is fragmented in five facets according to a vertical axis: context, procedural and opinion, and a horizontal axis: declarative, procedural (in the center) and intentional. Once the concept of competence was specified, in particular its relationships with the experience and the knowledge, we emphasize the propagation of the logic of the competences in all the current society. The transferability of the competences, stemming from a fine analysis of the experiences, seems considerable in any situation. After the presentation of two examples, we arrive at the conclusion that the interview of explicitation, by helping to extract competences of its diverse experiences, is a precious tool to become aware of possibilities of reinvestment and of valuation of the previous activities.