There was no substantial difference in performance between the subjects using the monitor or HMD. Therefore, for a simple task, similar to this experiment the most cost effective visual mode would be preferable. The monitor system provide a satisfactory method of displaying the visual information.
After the experiment, the subject performed one last trial using the opposite visual mode they had in the experiment. They were then asked which mode they preferred. Their response distribution is shown below.
Sixty five percent chose the method they used most during the experiment. This is likely, since they got accustomed to that visual mode. Reasons given by the subjects who disliked the HMD included the difficulty in adjusting the HMD, the HMD felt to confining, and not being able to see the hand controller. The HMD advocates noted the better field of view. Some of the subjects liked having the stereoscopic view of the HMD, even though it wasn't essential. Others found the 3-D distracting. However, all the subjects felt they could perform the task using only the monitor.
However, the unique feature of head-coupled tracking is the added benefit of using HMDs. Determining the use of HMDs in tracking tasks still depends on a number of factors, though. The tracking tasks typically involve a period of time that is uninterrupted by external visual stimuli. Although resolution of the HMD may be sacrificed, HMDs tightly couples head input motion with visual output, which does not deviate far from how people normally track and scan the world. The issues of lag and frame rate must also be considered in the device assessment.
The use of a two-dimensional track has not been common in previous tracking studies; past studies involving tracking have typically used a single-axis path, and allowed the subject to track to a particular target located on the path. The next logical step in furthering this research is to compare the performance of track navigation, using tracks similar to our experiments, between HMD with head tracking and static display with hand-controlled tracking.
Since one of the advantages of a head mounted display is the large field of view. A study looking into field of view of monitors could be performed. How does performance improve as the viewing display becomes larger. This study used 7.5 inch monitors. A further study could see how performance changes using different size monitors. This study showed that it may not be worth using an HMD, but a larger monitor may increase performance.