larry@uunet.uu.net (Larry Lippman) (10/01/90)
In article <12785@accuvax.nwu.edu> johnp@hpgrla.gr.hp.com (John Parsons) writes: > When Touch*Tone first came out, I remember my father griping that > the number pad was arranged differently from that of ten-key adding > machines, ... > Does anyone remember why Bell chose to be different? During the late 1950's Bell Labs conducted extensive human factors studies to ascertain the "ideal" key layout for a pusbutton dial. The result was the touch-tone dial layout that we have today. For those who may be interested, the study was published in the "Bell System Technical Journal" in July, 1960, and entitled: "Human Factors Engineering Studies of the Design and Use of Puhbutton Telephone Sets". There were five basic designs tested, having the following test results: 1. "Reverse Adding Machine" 1 2 3 Keying time: 6.01 sec 4 5 6 % errors: 2.5 % 7 8 9 Votes for: 3rd 0 Votes against: 2nd 2. "Two Horizontal Rows" Keying time: 6.17 sec 1 2 3 4 5 % errors: 2.3 % 6 7 8 9 0 Votes for: 1st (most) Votes against: 4th 3. "Two Vertical Rows" 1 2 Keying time: 6.12 sec 3 4 % errors: 1.3 % 5 6 Votes for: 5th (least) 7 8 Votes against: 1st (most) 9 0 4. "Telephone Dial" 3 2 Keying time: 5.90 sec 4 1 % errors: 2.0 % 5 Votes for: 2nd 6 Votes against: 5th (least) 7 0 8 9 5. "Speedometer" 5 6 Keying time: 5.97 sec 4 7 % errors: 3.0 % 3 8 Votes for: 4th 2 9 Votes against: 3rd 1 0 Note that the chosen key layout was a *compromise*. Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" {boulder||decvax||rutgers||watmath}!acsu.buffalo.edu!kitty!larry VOICE: 716/688-1231 || FAX: 716/741-9635 {utzoo||uunet}!/ \aerion!larry
ben@hpcvlx.cv.hp.com (Benjamin Ellsworth) (10/03/90)
> There were five basic designs tested, having the following > test results: It is interesting to note that the adding machine keypad layout was not tested. Perhaps NIH on the part of AT-n-T? Benjamin Ellsworth ben@cv.hp.com All relevant disclaimers apply.