From: Bob Jacobson Subject: Re: PHIL: Discussions about VR definitions Date: Thu, 11 Apr 1996 02:50:09 -0700 Message-ID: <316CD5D1.2E92@worldesign.com> Organization: Worldesign Inc., Seattle Dr. John V. Draper wrote: > As immersion is a perceptual phenomenon, how can one measure it > without soliciting user opinions? The idea of "voting" is not a good > example of how to do this, but there is a long history of techniques > for calibrating and using human reports to measure phenomena like > this. It takes some training and some skill, but it can be done > reliably. The problem is slightly more complicated. As immersion is a continuous process, measurements taken at points in time might vary according to the momentary sensation or experience of immersion. An analog measure- ment that fluctuated with the participant's experience of immersion would be a more reliable indicator of immersion, but one considerably more difficult to calibrate and compare from participant to participant. Similarly, assessing the participant's ability to carry out tasks -- the usual way of measuring degree of immersion -- also must be continuous. The resulting output of an immersion measurement would likely resemble an EEG or Richter Scale report on an earth tremor, rather than a single value. I'm unaware, however, of any measure of immersion used so far that has applied this obvious qualification. Bob Jacobson Worldesign Inc. Seattle