Development and Evaluation of a Virtual Reality Training System Based on Cognitive Task Analysis: The Case of CNC Tool Length Offsetting

This article reports on the development and evaluation of a virtual reality training system (VRTS) for a specific machining task. A cognitive task analysis of expert machinists was conducted to examine whether this can be effective in developing a VRTS concerning tool length offsetting for a machining center. This analysis provided the necessary information for development and calibration of such a system. Subsequently, the effectiveness of the VRTS was evaluated by conducting an experiment with 29 mechanical engineering students. The VRTS set-up comprised a video projection of the machining center and a physical mock-up of its interface. The system demonstrated positive training transfer for the toll length offsetting task in terms of task accomplishment and of time to complete the task. No positive transfer was observed in terms of task accuracy, probably due to perceptual biases induced by the detailed specification of the VRTS. The present work provides evidence that cognitive task analysis was effective in identifying a number of key skills pertaining to the tool length offsetting task and in implementing ways to facilitate training in such tasks in a virtual environment. This article also demonstrates that even for tasks that include subtle perceptual skills VRTS may be beneficial regardless of the level of physical fidelity, provided that the cognitive organization of a task is adequately mapped in the system. (C) 2014 Wiley Periodicals, Inc.