Carrying out a diagnostic interview requires skills that need to be taught in a controlled environment. Virtual Reality (VR) environments are increasingly used in the training of professionals, as they offer the most realistic alternative while not requiring students to face situations for which they are yet unprepared. The results of the training of diagnostic skills can also be generalized to any other situation in which effective communication skills play a major role. Our aim with this study has been to develop a procedure of formative assessment in order to increment the effectiveness of virtual learning simulation systems and then to assess their efficacy.