From: Chris Shaw [cdshaw@cs.uregina.ca] Sent: Tuesday, November 16, 1999 2:12 AM To: 3d-ui@hitl.washington.edu Subject: Re: exo- vs. ego-centric tasks Doug, > So, two questions: > 1. Are tasks inherently exocentric or egocentric? I would say first that "inherently" is the wrong word. Perhaps I'd couch it in terms of effectiveness. That said, I'd say that tasks requiring self-locomotion are egocentric. On the other hand, finding an efficient route is exocentric. That is, it is often better to use a map. There is a caveat, in that there is a major sex difference with map-based navigation vs landmark-based navigation. Men do better at map-based navigation, and women do better at landmark-based navigation. > 2. If so, what are some examples of each? > > My current list for #2, which I'm not satisfied with: > exocentric: puzzle assembly, global spatial relationships, surgery,... > egocentric: line of sight tasks, driving, local spatial relationships... exo: manipulating anything smaller than you ego: moving through a space larger than you ego: flying a plane As I think about it, the real issue might be relative size. Certainly real relative size is important, as in real locomotion or assembly. Maybe "virtual" relative size is important also, as in the "fantastic voyage" version of keyhole surgery. Technique like Worlds In Miniature are likely exploiting the observation that exocentric navigation is faster. -- Chris Shaw University of Regina cdshaw@cs.URegina.ca Assistant Professor Acting Director Institute for Computational Discovery, UofR http://www.cs.uregina.ca/~cdshaw