... Craig A: Understanding virtual reality: Interface, application, and design California: Morgan Kaufmann; 2002. 7. Stanney KM: Handbook of Virtual Environments: Design, Implementation, and Applications ... abilities, a safe testing and training environment, the opportunity for graduated exposure to stimuli, the ability to distract oraugment the performer's attention, and perhaps mostimportant to therapeutic ... virtualto the physical environment is greater if the learner isimmersed in the training environment [13]. Perhaps then the most important and defining factor for VR is the senseof presence of the...