Solid evidence of virtual reality's benefits has graduated from impressive visual demonstrations to producing results in practical applications. Further, a realistic experience is no longer immersion's sole asset. Empirical studies show that various components of immersion provide other benefits - full immersion is not always necessary. The goal of immersive virtual environments (VEs) was to let the user experience a computer-generated world as if it were real - producing a sense of presence, or "being there," in the user's mind.

In recent years, consumers have witnessed a technological revolution that has delivered more-realistic experiences in their own homes through high-definition, stereoscopic televisions and natural, gesture-based video game consoles. Although these experiences are more realistic, offering higher levels of fidelity, it is not clear how the increased display and interaction aspects of fidelity impact the user experience. Since immersive virtual reality (VR) allows us to achieve very high levels of fidelity, we designed and conducted a study that used a six-sided CAVE to evaluate display fidelity and interaction fidelity independently, at extremely high and low levels, for a VR first-person shooter (FPS) game. Our goal was to gain a better understanding of the effects of fidelity on the user in a complex, performance-intensive context. The results of our study indicate that both display and interaction fidelity significantly affect strategy and performance, as well as subjective judgments of presence, engagement, and usability. In particular, performance results were strongly in favor of two conditions: low-display, low-interaction fidelity (representative of traditional FPS games) and high-display, high-interaction fidelity (similar to the real world).

Virtual reality training systems are commonly used in a variety of domains, and it is important to understand how the realism of a training simulation influences training effectiveness. We conducted a controlled experiment to test the effects of display and scenario properties on training effectiveness for a visual scanning task in a simulated urban environment. The experiment varied the levels of field of view and visual complexity during a training phase and then evaluated scanning performance with the simulator's highest levels of fidelity and scene complexity. To assess scanning performance, we measured target detection and adherence to a prescribed strategy. The results show that both field of view and visual complexity significantly affected target detection during training; higher field of view led to better performance and higher visual complexity worsened performance. Additionally, adherence to the prescribed visual scanning strategy during assessment was best when the level of visual complexity during training matched that of the assessment conditions, providing evidence that similar visual complexity was important for learning the technique. The results also demonstrate that task performance during training was not always a sufficient measure of mastery of an instructed technique. That is, if learning a prescribed strategy or skill is the goal of a training exercise, performance in a simulation may not be an appropriate indicator of effectiveness outside of training-evaluation in a more realistic setting may be necessary.

3D UIs are uniquely able to achieve superior interaction fidelity, and this naturalism can be a huge advantage.