2.2.2. Desktop Virtual Reality
Classroom uses of virtual reality are limited, primarily due to the high cost of VR systems. For this reason, the term ``virtual reality'' has been applied more widely to include desktop virtual reality \cite{Winn93}. VR applications on the personal computer allow users to walk through simulated environments created via readily available commercial software, such as Virtus WalkThrough. Some slightly more expensive systems add peripheral devices, such as datagloves, joysticks, headmounts, or tracking, which plug directly into the desktop to provide a higher degree of interactivity.
Consequently, the VR projects developed using these low-end technologies are limited in size and complexity, and lack immersive and interactive qualities. Typical projects resemble 3D multimedia simulations and may involve the creation of simple models and minimalist worlds, which can be experienced via ``walkthroughs''. Certain efforts are worth noting, such as Grove's attempt to recreate historical contexts in VR \cite{Grove96}, but continue to remain rather passive simulations of limited detail. Perhaps the most significant use of desktop VR systems is in the education of learners with special needs or learning disabilities, who may not otherwise be able to experience certain aspects of the physical world. In this case, other types of VR systems may be unusable due to health, safety, and ethical reasons \cite {Cromby95}.
The integration of Internet and VRML software into the desktop configuration have expanded the usage of virtual reality in the classroom and added access to networked worlds, such as the ones described in the previous section. Research institutes such as The Virtual Reality and Education Laboratory at East Carolina University are also helping expand the use of VR at the level of the individual teachers by providing information about VR software for use in the classroom \cite {Pantelidis93}. Although educators may be willing to incorporate VR in their teaching practices, the introduction of VR in the classroom may bring with it multiple problems, including issues of funding, safety, teacher and student training, reshaping the curriculum, technological anxiety and confusion \cite {Bricken91}. Any efforts rely on the individual action of the teachers, who may need to convince reluctant administrators, colleagues, and parents of the value of VR in their classroom.