From: mbernat@gel.ulaval.ca (Marc Bernatchez)
Subject: PHIL: Discutions about VR definitions
Date: Wed, 03 Apr 96 21:37:13 GMT
Organization: dep. de Genie electrique


From: mbernat@gel.ulaval.ca (Marc Bernatchez)

vanevery@blarg.net (Brandon J. Van Every) wrote:
>
>Marc Bernatchez (mbernat@gel.ulaval.ca) wrote:

>: >: >>: 	1- 3D imagery -> 0% in text based MUDs
>: >: >>: 	2- Immersion   -> 0% or very poor
>: >: >>: 	3- Interaction (real-time response) -> 70%
>: >: >>
>: >: >>: average score: 23%
>: >: >
>
[...]

>: I didn't felt that way Brandon. I, for one, welcome such qualitative
>: inputs even if I opted for a more numerical approach. Well, yes, I do
>: admit that I tend to be more on the technical side. By example, to me,
>: VR is a very technical thing. You must use technological means to
>: achieve VR in my mind.
>
>Sure... I would just like to see statistical tolerances on the order
>of +- 5% at a bare minimum.  In my mind, the scientific purpose of
>using numbers is to increase accuracy.  

Brandon, it does. Read my last post again.

>Also, the "thing" to be
>measured should be something other than a user opinion poll.  I don't
>know/care whether 10,000 people think that "textual VR" has a "very
>poor degree of immersion" or whatnot.  

Well, I do care of what 10,000 people and up would have to say about
this issue. Don't underestimate people's intelligence. The more people
are involved in such a vote, the greater the chance that the
interpretation of the term "immersion" is correct in regard with the
final score I would get. That is, given that the voters are
knowledgeable enough about VR. It's my opinion. You know, every term
is strongly subject to interpretation. The thing to see here is that
even if it sounds very vague to you what these VR related terms really
does mean, they are very focused terms. Ask people on the streets what
is "immersion", "FOV", "angular resolution". There you will get very
sparse definitions or none because these are very specific VR related
terms. For us, in the field, it sounds large, but for them it is all
the same at the limit.

>Used here, the qualitiative
>definition of "immersion" is too imprecise to support any form of
>measurement whatsoever.  We need to be discussing how to make it more
>qualitatively precise, and not trying to quantify something which is
>hopelessly vague.

I totally agree and would never ask people to vote just like that. I
would first define each terms qualitatively prior to asking them to
take a vote. The textual definition would also incorporate sort of a
qualitative to quantitative conversion scale.

>FOV is a stab at the problem, but it has a very narrow focus.  It's
>emminently measureable, but it doesn't really address the "immersion"
>question.  Which is why I said "better FOV leads to better FOV."

Sorry but I disagree. FOV and immersion are strongly related. Let's
take an HMD for example. Under a certain degree of FOV, you see the
borders of the images the HMD produces. If the FOV is large enough,
these boundaries disappear. It is qualitatively known that somewhere
near that point where the boundaries disappears, the immersion level
begin to increase dramatically.  There exist literature about that.

>Also, for methodology: why give a weighted measure to "3d imagery,"
>when it's a binary concept?  Are there systems which exist in a
>hypothetical continuum between text and 3d imagery?

Simple mathematics Brandon... Use 0% (if not present) or 100% (if
present)

;)

Why not? this enables you to mix binary and more gradated data in your
global evaluation. There's nothing wrong with that.

>As for "interaction or real-time response," are we talking about lag?
>What sort of lag?  The speed at which text appears on the screen?  The
>speed of the typist?  What are we comparing this measurement to?  The
>speed at which an HMD can track and deliver an augmented 3d image?  We
>can compare the speeds, but are the information domains comparable?

Not necessarily lag. See it as very general as the term "interaction"
is concerned. I mean that the way immersion may be degraded is not
important here. You evaluate in function of the global
"responsiveness" of the whole VR system. I'm sure you will argue that
we can't put that in % not knowing how 10 ms delay is in regard to X%
of interactivity. I agree. Then again, I would first try to define a
conversion rule with the help of others in the field.

>: An artist claimming that his paints are virtual
>: worlds don't understand the term VR as I do. This kind of spreading of
>: the term VR is what caused so much hype around. At the limit, every
>: thing is VR.
>
>Ok, but let's get back to this question of "is textual VR really VR."
>One possibility is to put up strictures like "it must have 3d."
>That's comparable to saying "we don't really want to deal with the
>issue."  That particular qualitative criteria says "no 3d = no VR."

I strongly disagree. Quite the contrary, we want to deal with this
issue so much that we try to get some definitions around clearer and
less ambiguous.

>There's no point in trying to add additional authority via
>statistics.  The authority is already vested in a scientific
>community that doesn't want to discuss non-3d options, as a matter of
>research perogative.

Well, that's the way things are. We have to reject some parts that
gets to far away from the definition most of the people in the field
believe to be the best.

Non-3D solutions are not considered a bad approach. It's just that
it's not called VR then. Why would everything fit in VR? We get back
to what I said at the end of my last post. That is, that everybody
wants his piece of the cake in regard to the actual VR momentum.

>A lot of people get around the problem of needing to talk about 3d and
>VR hardware, by instead discussing "Virtual Environments" or "Virtual
>Worlds."  

This is regrettable to my view. These terms are used as "patch words"
when you don't want to get to mess with the VR definition
problems. I'm not afraid to use the term "VR". I do understand what it
means and I can explain it if someone ask me how I see VR.

I think it would be a good time at this point of our debate to tune
our WWW browsers to two great sources of definitions on the net
regarding VR. These are the "VR glossary" and "VR Terms by Joe Psotka
and Sharon Davison". These texts are all available via our site
VResources(see at the end for the link).  Go in the VR Article section
and then find these two in the section where it says "Virtual reality
(all sort of written documents)". You can also find these texts from
the sci.vw WWW site.

>This leads to a question: what forms of "immersion" are
>intrinsic to 3d and/or VR hardware, and what forms are cleanly
>separable?  It is within this latter domain, that people generally
>attempt to advance the claim that textual MUDs are, in fact, VR.  It
>is also within this latter domain, that people attempt to claim that
>just about anything and everything, however spurious, is VR.
>
>Anyone want to try to put Occam's Razor to this one?  :-)
>
>: Most importantly, once a definition has
>: been reached, we must educate the public so that they are able to
>: discriminate by themselves. This way only would the hype diminish and
>: hopefully dissapear.
>
>I'm afraid that the marketers will always shout louder and with more
>dollars than the scientists.  :-)

Let's keeps our hopes high Brandon :-). You have a point here but I
think that if we show enough determination, we'll get to have our word
to say on that matter. Let's not forget who brought the VR technology
to life... these very scientists, not the business men.

>Cheers,

Nice discussion Brandon, I appreciate a lot.

Cheers

 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