Navigating overlapping virtual worlds: Arriving in one place and finding that you're somewhere else

When a person moves through an overlapping environment they can travel in a closed, Euclidean loop but still end up in a different place to where they started. Although such environments are unusual, they do confer potential advantages for navigation. Three independent attributes of spatial overlap, as applied to 3-D virtual environments (VEs), are described, together with their likely effects on navigation. An experiment that investigated one ty pe of overlap (loop connectivity) is described. Participants learned spatia l knowledge more slowly in an overlapping VE than in a conventional VE, but the differences were small and, after initial navigation, not significant. Therefore, there seems to be no cognitive barrier to the useful implementa tion of overlapping VEs within a wide variety of applications.