Comments on: The Emerging Math/Rules of Social Networks – Magic Numbers http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/ Fri, 28 Oct 2011 01:28:22 -0500 http://wordpress.org/?v=2.8.4 hourly 1 By: Ton Zijlstra http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-206985 Ton Zijlstra Sat, 10 Jan 2009 20:22:23 +0000 http://www.fastforwardblog.com/?p=1269#comment-206985 No problem at all Rob. Thanks for pointing to my old stuff. No problem at all Rob. Thanks for pointing to my old stuff.

]]> By: Rob Paterson http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-206980 Rob Paterson Sat, 10 Jan 2009 19:47:13 +0000 http://www.fastforwardblog.com/?p=1269#comment-206980 I have fixed it - Ton sorry about that Rob I have fixed it – Ton sorry about that
Rob

]]> By: Ton Zijlstra http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-206899 Ton Zijlstra Sat, 10 Jan 2009 07:52:16 +0000 http://www.fastforwardblog.com/?p=1269#comment-206899 Hi Rob, I think you meant to refer to this March 2004 posting: http://www.zylstra.org/blog/archives/2004/03/dunbar_number.html Hi Rob, I think you meant to refer to this March 2004 posting: http://www.zylstra.org/blog/archives/2004/03/dunbar_number.html

]]> By: Robert Paterson http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-206277 Robert Paterson Wed, 07 Jan 2009 13:44:54 +0000 http://www.fastforwardblog.com/?p=1269#comment-206277 Weird - sorry about that Ton - it was a couple of years back and I must have done it wrong - do you recall writing about these kinds of numbers - maybe we can resurrect the right link Rob Weird – sorry about that Ton – it was a couple of years back and I must have done it wrong – do you recall writing about these kinds of numbers – maybe we can resurrect the right link
Rob

]]> By: Ton Zijlstra http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-206210 Ton Zijlstra Wed, 07 Jan 2009 08:05:31 +0000 http://www.fastforwardblog.com/?p=1269#comment-206210 Hi Rob, thanks for a worthwile overview. The link you've added to my name points actually to an article of yourself, the brief survey you link to in the paragraph above. Hi Rob, thanks for a worthwile overview. The link you’ve added to my name points actually to an article of yourself, the brief survey you link to in the paragraph above.

]]> By: Harold van Garderen http://www.fastforwardblog.com/2009/01/03/the-emerging-mathrules-of-social-networks-magic-numbers/comment-page-1/#comment-205742 Harold van Garderen Mon, 05 Jan 2009 13:13:42 +0000 http://www.fastforwardblog.com/?p=1269#comment-205742 Hi Rob, Good post, neat summary. One suggestion. The mentioned range 5 (minimum), 7 (brain number), 8 (military choice) can be summarized as 7 +/- 2. 7-2 = 5, leading to 5, 25, 125 7+2 = 9, leading to 9, 81, 729 I'm from an R&D environment and we have noticed the following: 9 is the maximum size for a creative group. Go over 9 and the group will effectively split in two. And indeed, go below 5 and you loose the creativity. 81 is the maximum size of a productive project. Often consisting of 9 teams of 9 people. Go over 81 and the project will fail (start debating, split, etc). Also, a good-performing projectteam of 81 that must speed up is REDUCED in size by at least 15 FTE to reduce internal discussion (= faster completion). R&D locations of over 729 people (9 projects of 81 members) are sub-optimal and non-manageable. I guess someone else can give a similar example for the 5, 25 and 125 lower limit. Hi Rob,

Good post, neat summary. One suggestion.

The mentioned range 5 (minimum), 7 (brain number), 8 (military choice) can be summarized as 7 +/- 2.

7-2 = 5, leading to 5, 25, 125
7+2 = 9, leading to 9, 81, 729

I’m from an R&D environment and we have noticed the following:

9 is the maximum size for a creative group. Go over 9 and the group will effectively split in two. And indeed, go below 5 and you loose the creativity.

81 is the maximum size of a productive project. Often consisting of 9 teams of 9 people. Go over 81 and the project will fail (start debating, split, etc). Also, a good-performing projectteam of 81 that must speed up is REDUCED in size by at least 15 FTE to reduce internal discussion (= faster completion).

R&D locations of over 729 people (9 projects of 81 members) are sub-optimal and non-manageable.

I guess someone else can give a similar example for the 5, 25 and 125 lower limit.

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