<Cynicism> I always figured it was based on the number of managers that you have on the project, one manager for each layer... At least that is how it was done at a previous company I worked for... </Cynicism> Models are very nice to help you get people to think about something the same way. Of course the best engineers that I know, understand the model, but think way outside it... Letting unique solutions that break the model, but deliver better results... Bill -----Original Message----- From: owner-ietf@ietf.org [mailto:owner-ietf@ietf.org] On Behalf Of Dave Crocker Sent: Tuesday, October 08, 2002 12:25 PM To: Robert Elz Cc: ietf@ietf.org Subject: Re: TCP/IP Terms At 11:38 PM 10/7/2002 +0700, Robert Elz wrote: >Attempting to give these things absolute numbers, other than for ease >of reference in some particular context is lunacy. Not that I disagree with your primary point, it is worth noting that there is some basis for hovering about 7, for an *overall* model. It's that memory limit thing (7, plus or minus 2.) The plus or minus is statistical, so if you want to make sure that people really have no trouble grokking the total set, 5 is a better choice. d/ Dave Crocker <mailto:dave@tribalwise.com> TribalWise, Inc. <http://www.tribalwise.com> tel +1.408.246.8253; fax +1.408.850.1850