Roy Ruddle: Navigating Discontinuous Virtual Worlds

Project title: Navigating discontinuous virtual worlds: The role of cognitive maps and wayfinding aids

Investigators: Dr Andrew Howes, Prof Dylan Jones, Proj Stephen Payne, and Dr Roy Ruddle

Funding: EPSRC (1997-8)

Note: this research took place while Roy Ruddle was employed at Cardiff University

A central characteristic of conventional virtual worlds is that they present environments in terms of 3-D continuous Euclidean space through which people travel. Other, novel classes of virtual world are those in which the real world rules of spatial structure are sometimes violated. These environments contain discontinuities of movement (hyperlinks) or space (overlap) which confer potential advantages in terms of the design of flexible layouts and reduced navigation time, in the same way as hypermedia offers advantages over conventional books. Many examples of large-scale, discontinuous virtual worlds are already in the public domain, but experience shows that the advantages offered by the use of these worlds are sometimes outweighed by the cognitive difficulties that are caused to people by the discontinuities.

In a 1-year project, titled "Navigating Discontinuous Virtual Environments: The Role of Cognitive Maps and Wayfinding Aids" and which was funded by the EPSRC, we set out to explore the navigational and cognitive effects of hyperlinks and overlap when they occur in virtual worlds. Hyperlinks allow speedy spatial browsing but have a detrimental effect on rate at which people develop spatial knowledge, when compared with conventional virtual worlds. Investigations which used ghost-like doors (doors which people walked through, rather than opened) suggest that it is the break in visual continuity that occurs when people traverse hyperlinks, rather than the lack of continuous motion, which makes the greatest contribution to the navigational problems that are experienced with hyperlinks.


Figure 1: Hyperlinks in an experimental virtual world

Surprisingly, virtual worlds which are designed so that they drastically overlap when mapped to Euclidean space cause only modest navigational difficulties. It seems that people can learn these confusing spatial layouts more easily than they can learn layout of hyperlinked worlds, but the exact form of their mental representation of the former remains unknown.

The following video clips show examples of the discontinuous virtual environments that were investigated during the experimental programme. Each clip lasts between 1 and 2 minutes and is in QuickTime VR format:

Results from this project were the subject of an invited talk given at the workshop on Spatial cognition in real and virtual environments at the Max Planck Institute, Tuebingen (1999).

Final Report

A summary of our final report to the EPSRC is available on-line.

Project's publications

Ruddle, R. A., Howes, A., Payne, S. J., & Jones, D. M. (2000) The effects of hyperlinks on navigation in virtual environments. International Journal of Human Computer Studies, 53, 551-581.

Ruddle, R. A. (2000). Navigating overlapping virtual worlds: Arriving in one place and finding that you're somewhere else. In C. Freksa, W. Brauer, C. Habel, & K. F. Wender (Eds.), Lecture notes in artificial intelligence 1849: Spatial cognition II, 333-347. Springer.

Ruddle, R. A. (2001). Navigation: Am I really lost or virtually there? In D. Harris (Ed.) Engineering psychology and cognitive ergonomics (volume 6), 135-142. Burlington, VT: Ashgate.