At the end of the session, they completed a second knowledge questionnaire to assess the contribution of Simubat 4.0 Gen-2 and the Computer System Usability Questionnaire (CSUQ) about their experience with VR and MR. The CSUQ was developed and validated within IBM in 1995 by Lewis [29]. This standardized questionnaire is a derivative of the Post Study System Usability Questionnaire (PSSUQ) [30]. This questionnaire is used to measure the usability of a system, the system's performance in performing a task, and the user's satisfaction. The CSUQ questionnaire comprises three dimensions in addition to the overall score. The first dimension evaluates the usefulness of the system ("Overall, I am satisfied with how easy it is to use this system."), the second dimension is the quality of information ("The system gives error messages that clearly tell me how to fix problems.") and the third dimension concerns the quality of the interface ("The interface of this system is pleasant."). The score for each dimension was obtained by averaging the items concerned.