In discussing these areas, it should be noted that the recommendations have not been prioritized in any detailed manner. This is due primarily to our judgment that successful development and application of SE systems depends on an entire matrix of interrelated factors. We nevertheless feel that it is important to stress the crucial need for improved hardware technologies to enable development of improved interface devices and improved computer generation of multimodal images. Unlike the situation in the area of teleoperation, in the area of VEs there are relatively few individuals who have primary interests or backgrounds in hardware; most individuals in the VE area are involved primarily in the software end of computer science, in communication or entertainment media, and in human perception and performance. Thus, the importance of adequate hardware, without which the VE field will never come close to realizing its potential, tends to be underplayed by the VE community. A somewhat similar comment concerns the issue of user comfort. To date, a very large fraction of VE usage has occurred in the context of short demonstrations, a context in which the degree of comfort is relatively unimportant. However, if the comfort of VE systems (particularly head-mounted displays) cannot be radically improved, the practical usage of these systems will be limited to emergency situations or to very short time periods. In other words, adequate comfort, as well as technically adequate hardware, are essential to realizing the potential of the SE field.
Finally, it should also be noted that our thoughts about government policy and infrastructure are stated as comments and suggestions rather than as recommendations. They are based solely on the experience and judgment of the committee members.
Significant research and development is taking place in a wide variety of application domains, and in some cases the results of this work are beginning to be applied on an experimental basis. Although it is not yet clear which tasks will eventually gain the most from the use of SE systems, the committee has identified four application domains that show particular promise: (1) design, manufacturing, and marketing; (2) medicine and health care; (3) hazardous operations; and (4) training.
Other important application domains that are assigned lower priority are education, information visualization, and telecommunications and teletravel. The application domain of education is of critical concern;