Évaluation des performances et de la charge de travail induits par l'apprentissage de procédures de maintenance en environnement virtuel

Résumé Fr En

L’objectif de cette étude était de vérifier comment se déroule l’apprentissage d’une procédure en environnement virtuel d’apprentissage d’opérations de maintenance de chars : GVT (Generic Virtual Training). Des mesures comportementales (temps de réalisation de la tâche, nombre et durée de consultation des instructions, nombre d’actions incorrectes) et des mesures subjectives de la charge de travail (réalisées avec NASA-TLX) ont été recueillies chez 15 individus lors de l’exécution d’une procédure. Celle-ci faisait l’objet de 10 répétitions successives par les participants puis 3 nouvelles répétitions après quatre jours d’intervalle. En accord avec les théories proposées par Fitts (1964) et Anderson (1983, 1995), les résultats montrent que l’apprentissage de la procédure s’effectue selon 3 phases (cognitive, associative et autonome). Au plan factuel, l’évolution des performances prend l’allure d’une courbe d’apprentissage et s’accompagne d’une diminution de différents facteurs constitutifs de la charge de travail. Les performances observées lors de la réalisation de la procédure après délai attestent de son stockage en mémoire à long terme.

Learning a procedural task in a virtual environment for training: evaluation of performance and workloadThe aim of this study was to investigate procedural learning using a virtual environment for training : GVT (Generic Virtual Training). Performance (time to carry out the task, number of readings of the instructions, time needed to read the instructions, number of incorrect actions) and subjective workload (assessed with NASA-TLX) were measured while and after the carrying out of a procedural task dealing with tank maintenance. Fifteen participants were asked to carry out the task for ten consecutive trials. Volunteers had to re-run the task for three more trials after a four days delay. The results reveal that the total time to perform the task, as well as reading the instructions, the execution times and the number of errors, decrease along with the repetition of the trials, showing a learning curve. Moreover, after four days, these results were similar to those observed at the end of the first set of trials. These results show that the procedure seems to be acquired, that is stored in the learners’ Long Term Memory. In addition, turning to subjective workload measures, subscales such as mental demand, physical demand, performance, effort and general workload, seemed to follow the same pattern, thus showing decreasing cognitive demand and increasing performance along with procedural skill acquisition. These findings are congruent with the theoretical framework proposed by Fitts (1964) and Anderson (1983, 1995), and suggest that procedural learning occurs following three stages: cognitive, associative and autonomous. During the cognitive stage, learners strongly rely on procedural instructions to carry out corresponding actions. Because this stage requires many attentional resources, it makes a heavy use of cognitive processes. In the associative stage, learners make a transition from a slow and deliberate use of the knowledge delivered by the instructions to a more direct representation of what to do. Errors that might have occurred in the cognitive stage are gradually detected and eliminated, leading to successful performance of the procedure. Finally, when the procedure has been repeated a certain number of times, it becomes more and more automated and rapid, and requires few attentional resources. In this autonomous stage, the procedural skill is revealed by errorless rapid performance. To conclude, using a simple instruction following paradigm, this study showed that a Virtual Environment for Training can help individuals to effectively learn a new procedure effectively, i.e., store it in their long term memory so that it could be reused later.