Path: utzoo!telecom-request Date: 23 May 91 16:44:56 GMT From: oberman@ptavv.llnl.gov Newsgroups: comp.dcom.telecom Subject: Re: Why Are *Telephone Keypads* Built Upside Down Message-ID: Organization: TELECOM Digest Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 393, Message 11 of 14 Lines: 32 In article <8755@drutx.ATT.COM> mcp@drutx.ATT.COM (Mike Paugh) writes: > What I have always been told, and this is _pure_ folklore with no > facts to back it up, is that the keypad was originally the same > as that of a ten key adding machine. People who used these machines > were so adept at using the keypad that the telephone systems would > miss digit when the person keyed them too quickly. The upside down > arrangement was used intentionally to slow people down so that the > digits could be recognized. This is the reverse of the true story. Bell Labs did extensive testing of keypad layouts back before the first Touch-Tone phones were buile and found that there were far fewer dialing errors from the average user when the keypad was in the top to bottom order. This is documented in an old Bell Tech Journal. I think the typical user was also faster on this arrangement, but I don't remember for sure. AT&T was concerned with errors since they cost AT&T $$$. Remember that the typical telephone user has never become proficiant with an adding machine keypad. And the number who were was far smaller in the late 50s when Bell Labs was doing the research. R. Kevin Oberman Lawrence Livermore National Laboratory Internet: oberman@icdc.llnl.gov (415) 422-6955 Disclaimer: Don't take this too seriously. I just like to improve my typing and probably don't really know anything useful about anything. Especially anything gnu.