Virtual reality is an immersive, interactive medium that manipulates the senses in order provide users with simulated experiences in computer-generated worlds. The visual design of virtual reality is an important issue, but literature has tended to stress the medium's instructional potential rather than setting forth a protocol for designing virtual environments. Furthermore, virtual reality is often considered a solution in search of a problem instead of a viable instructional tool. To counteract this notion, a study of technology designers, media experts, and instructional designers was conducted to share ideas and generate data regarding what constitutes an Instructional Virtual Environment (IVE), when one should be used, how best to design one, who should be involved in the design process, and how to evaluate one. Three rounds of Delphi surveys were administered by electronic mail, resulting in expert consensus on several points. Virtual reality (VR) is defined by the computer-mediated experiences it provides, and while it must be interactive, it does not require full immersion. VR should be used in educational situations requiring experience in particular settings, especially to present spatial or abstract information because of the advantages of sensorial feedback. The design of IVEs should consider constructivist learning principles, require a high level of user interaction, and support mastery learning. The design process should involve multi-disciplinary teams, including instructional designers, subject matter experts, end users, computer experts, ergonomic specialists, and artists. Finally, evaluators should study IVEs very thoroughly, examining all aspects of the environment and using many different methods. Qualitative data, focus groups, and comparative analysis are recommended directions for future study. (Contains 29 references.) (BEW)