Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: David Lewis Newsgroups: comp.dcom.telecom Subject: Re: Another Thought on 8-digit Phone Numbers Message-ID: <1812@accuvax.nwu.edu> Date: 4 Dec 89 18:59:16 GMT Sender: news@accuvax.nwu.edu Organization: Bellcore, Livingston, NJ Lines: 22 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 9, Issue 552, message 4 of 7 In article , ijk@violin.att.com (Ihor J Kinal) writes: > Somewhere I was told that the phone company [MA BELL] did studies in > the distant past, and found that people remember 7 digits much better > than 8. There's a famous work on short-term memory called "Seven Plus-or-Minus Two". I don't recall the author (I guess it's not *that* famous), but the basic conclusion is that a person's short-term memory can hold, on average seven "chunks" of information, plus or minus two. Of course, most people don't remember phone numbers as digits, but as collections of numbers. My phone number, for example, isn't stored in my memory as "2", "0", "1", etc..., but as "201", "758", "40", "99". Four chunks. Same with SSN -- "XXX", "XX", "XXXX". David G Lewis ...!bellcore!nvuxr!deej (@ Bellcore Navesink Research & Engineering Center) "If this is paradise, I wish I had a lawnmower."