From: Robin Hollands Subject: Re: HUMAN-FACTORS: Children, VR, and home entertainment Date: Thu, 21 Nov 1996 16:11:33 +0000 Message-ID: <32947F35.7786@shef.ac.uk> Organization: Automatic Control & Systems Engineering, University of Sheffield Marc Bernatchez wrote: > > 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. Don't patronise the public - just give them the facts. It should be worth also requesting that an 'engineer in training' only comments to the media on subjects he is experienced in. Regular newsgroup readers will remember that I mathematically proved Marc's 'quality of HMD' measure to be fundamentally faulted a few months back (the best HMD had a 0 degree field of view!). Although I appreciate Marc's enthusiasm in the subject and the amount of time he has devoted to making information freely available, I am also concerned that this has put him in a position to appear an expert on subjects he is clearly not. Marc's comments have often bought criticism both from established researchers, such as John, and high-end HMD manufacturers. What original research have you done in the area of HMDs, Marc? What peer-reviewed publications have you in the area? > 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. But having 20 arc minutes per pixel in a 20 degree FOV HMD is like having tunnel-vision, which is also a severe sight-defect! If you are going to argue your case, don't use figures of speech, anecdotes and generalisations. If you can give us *good* scientific findings and arguments to back up your view, then we will not be able to disagree. Your 'figure of speech' that one pixel looks like 1 meter square shows quiet how misleading (or just plain wrong) you can be. The actual cross sectional area a pixel represents will vary according to the distance away that the object is and will range between 0 and infinity on *any* HMD. OK, so I wouldn't do particularly well in a sight test in most HMDs, but they are perfectly adequate for looking around buildings etc. If you want to see the object in more detail - get closer! > 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. Is Marc implying that other researchers/developers disregard public safety? I've certainly not seen this in my contact with the VR industry, in fact quite the opposite often applies. If Marc is going to make such a serious accusation, I presume he has the solid facts to back it up. > 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. This is a common request and at one point UK VR-SIG tried to collect together papers from UK researchers. The fact is, however, that most publications require that you sign copyright over to the conference/publication company and therefore putting the documents on-line often in breach of copyright (even though you may be the author!). I will be chairing a one-day EPSRC workshop on 'Health and Safety of Virtual Reality Systems' at the Rutherford Appleton Laboratory on Thursday December 12 1996. You can find more info on the event at http://www.cis.rl.ac.uk/cclubs/VVECC/events/HSVR/ and some form of proceedings should be made available after the event. It will be interesting to see if the prominent researchers back up Marc's subjective arguments, but since I know much of the content already, I would not put any money on it! Since this group is obviously read by those interested in, but not necessarily experienced in the field, I would like to finish on a note of caution. This newsgroup may be moderated, but it is not peer reviewed. This means anyone can write pretty much anything and pass it off as the truth. Whilst free expression of opinion is genuinely useful, unfettered statement of fact is not. Before you put trust in any of the contributors to the newsgroup (especially me!), do some background reading. If in any doubt of the facts, check peer-reviewed literature. A peer-reviewed publication means that the scientific authenticity of the statements have been checked by others already acknowledged in the field. It's not a perfect system, but it's the best we have. And for anyone who continues to believe everything they read on the Web - boy, have I got a property deal for you! :-) Cheers, Robin (UK VR-SIG Chairman) Email: r.hollands@sheffield.ac.uk WWW: http://www.shef.ac.uk/~vrmbg/staff/rjh/rjh.html BOOK: http://www.shef.ac.uk/~vrmbg/vrhmhb/vrhmhb.html