An experimental evaluation of the sexology program was conducted at the University of Quebec at Montreal. Managers of the program, students, teachers and individuals and groups directly or indirectly involved in sexology look part in the Hammond evaluation. This article deals with the evaluation model inspired by Hammond Stake and Tyler. Questions raised at the outset by the institution about the objectives of all its baccalaureate programs and managers' concems about meeting the needs of future work situations led to the emergence of this model. Other circumstances did not fit the model. The final application of the model is presented. Questions are raised about the fate in program evaluation of models modified during the evaluation process.