From: Marc Bernatchez <mbernat@gel.ulaval.ca>
Subject: Re: HUMAN-FACTORS: Children, VR, and home entertainment
Date: Wed, 20 Nov 1996 13:40:32 -0500


>I've just read Marc's "interview" and I think the statements made are
>unwise and cannot be substantiated on our current knowledge.  I share his
>concern that we need to tread carefully in introducing "games" HMDs that
>may be used for very long periods.  But this "concern" has to be based on
>empirical data:
>
>We are one of the few research groups that has undertaken (and published)
>physiological measurements of the visual changes following HMD use and our
>1993 papers gave rise to the initial "scare" or "concern" about HMDs and
>shortly after that the "games HMD" to which Marc refers was postponed and
>still hasn't appeared.  I would stress, however, that the implications of
>our findings were exaggerated by the media and I would council Marc to
>guard against giving the media the fuel to do this again.

I must disagree with this statement. I don't "give the media fuel" to
exaggerate the implications a HMD could have on people. Anyway, I find
it way more wise to bring the general public (including the media, the
companies, etc.) to brake before they've done harm than the opposite.
Understand me here, I don't want to be of any nuisance to the VR
expansion.  Quite the opposite, I want the best for the VR field. BUT,
I will do so with respect to my ethics. Sometimes, it's better to
break people to better advance later than let them go full speed into
the wall.

Also, have you done any testing of these issues on young kids in the
8-15 years old range? If so, I would like to read your papers. To my
knowledge (that has much limits I freely admit), I don't know of any
such reports.

>Marc also suggests that some HMD companies have jumped on the bandwagon,
>without worrying about human-factors.  I have had contacts with a number of
>HMD producers/designers and we have undertaken appraisal work for some of
>them and I have certainly haven't encountered this attitude.  The
>manufacturers I know of consider the optical design of their devices as a
>priority issue.

As I said, let's not generalize. Many companies are going the right
way with this. Thought, when I see a 20 arc minutes per pixel HMD
being in use, no matter for what, I just can't say "everything is
fine". For those unfamiliar with the "arc minutes per pixel"
reference, let's just say that 20 for this reference is like being
blind (or almost). Note that this 20 am/p HMD may have been rigorously
designed optic wise. Then again, do you call optics that stretch
pixels that much that a pixel looks like 1 meter square(don't take me
literally here, this number is a figure of speech) a good design? I
don't.

>Yes, there are issues that arise for the design of HMDs, but these need to
>be considered through a clear, unemotive consideration of the
>vision-science findings. Lets work with the HMD industry, not against it,
>the last thing the industry needs is another scare of what "might
>be....if".

I agree totally. We do work with the industry. Thought, it's not
because it is hard at this moment for some to produce quality that we
should close our eyes and be tolerant. As an engineer in training, I
have certain rules to respect. One of these is to protect the
public. That should be the number one priority of any one in the VR
field reading this.

Nevertheless, I want to thank Mr. Wann for his constructive comments
on this. John, could you make some of your past papers electronically
available on-line? One big problem for many people is the lack of time
to look for/order paper material over normal post etc. I'd sure like
to read your documents.

Best regards


 Marc Bernatchez             |  E-mail: mbernat@gel.ulaval.ca
 C.O.P.L. (local plt-00307)  |============================================    
 Dep. Genie electrique       |  http://www.gel.ulaval.ca/~mbernat
 Universite LAVAL            |  http://www.imaginative.com/VResources
 Quebec, Canada              |============================================
 G1K 7P4                     | Virtual Reality is the future of computers
==========================================================================