Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!casbah.acns.nwu.edu!andersen!tsarver From: tsarver@andersen.uucp (Tom Sarver) Newsgroups: comp.human-factors Subject: Re: Touchscreens Message-ID: <1991Jun17.213728.20467@casbah.acns.nwu.edu> Date: 17 Jun 91 21:37:28 GMT References: <8435@awdprime.UUCP> <6460@ns-mx.uiowa.edu> Sender: news@casbah.acns.nwu.edu (Mr. News) Organization: Andersen Consulting Lines: 66 Nntp-Posting-Host: 192.42.140.1 In article <6460@ns-mx.uiowa.edu> jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes: >From article <8435@awdprime.UUCP>, by jon@kitty.austin.ibm.com (Werner): > >> Are there any papers written dealing with the use of touchscreens as an >> alternate input device in environments which don not have enough desk >> space for a keyboard or a mouse? > >I don't know of any papers, but as a long-term touch-panel user, I much >prefer mice, trackballs, or knobs on my keyboard. > >I used the U of Illinois Plato touch panels between 1973 and 1980, and >the big problems are: > > 1) You have to lift your hand up from the keyboard, perhaps a foot, > to touch the screen. This slows you down compared to horizontal > moves to a mouse. > > 2) No matter how good the anti-reflection coating on your screen is, > fingerprints tend to defeat it. If you've got a touch panel, you'll > need to wash it almost daily to keep the glare down. > > 3) If you have touch-intensive software, where you spend long periods > holding your hand up to the screen poking here and there, your arm > gets tired. I remember after some sessions debugging a particular > touch-intensive piece of computer aided instructional material, my > arm began to ache quite intensely. I've never experienced that kind > of reaction to "desktop pointers" like mice. > It appears that a touch-screen station would be designed in a completely different way than keyboard/mouse/screen combos are now. I suggest that a touch screen should have the monitor imbedded in the the desk pointing at the user with an adjustable angle to the desktop. This would be more natural in the way we deal with papers and pens and other items. (BTW, if you think about it, you don't want to judge an interface by the difficulties encountered by the developers. It's the users' opionons in which we're interested.) > 4) Touch panels aren't particularly accurate. Even if you use a modern > thin-film touch panel, there is a real problem with paralax. The > front of a CRT display is quite thick, and the push button size we > typically use with mice is small enough that it can be very hard to > find the right spot on the screen to touch to get a particular > button and not its surrounding area. The Iowa City Public Library > on-line card catalog has been touch screen based for a few years > now, and I've had numerous paralax problems with it, even thoug it > has nice big on-screen push buttons. > We should be able to use a stylus (sp?) or pen so that the computer is just one more thing we poke at. The optimal software would not require a keyboard at all. There should be some basic OCR which allows one to write letters (in print) which are replaced by text. Since it is interactive the OCR needs only about 80%-90% proficiency. This leans toward the attitude that the computer is simply a very flexible notepad. I realize I am basically describing a light pen interface, but the hardware is actually touch screen with the option of either stylus (hi-res input) or finger (lo-res input). > Doug Jones > jones@cs.uiowa.edu -- --Tom Sarver tsarver@andersen.com Andersen Consulting "Think straight; talk straight." 100 S. Wacker, Ste. 900, Chicago, IL 60606 (312) 507-4912 "If the Firm ever discovered my opinions, IT would summarily forget them."