Category: Resources

Some empirical support for the magic number 150

Two things:In the paper Co-evolution of….

Two things:

  1. In the paper Co-evolution of neocortex size, group size and language in humans, Robin Dunbar predicts that the maximum group size that humans can maintain as a cohesive social unit, based on the ratio of neocortex volume to brain volume, is 147.8 (100.2-231.1 at 95% confidence). Consulting the literature, he finds that there’s a trimodal distribution of group sizes: bands at 30-50 people, tribes at 1000-2000, and an intermediate one. The mean size of the intermediate level group societies is 148.4.
  2. The AOL Instant Messenger servers impose a hard limit on the number of people you’re allowed to put in your buddylist: 150.

(For more, and a better summary of Dunbar’s paper, read The Magic of 150. Malcolm Gladwell also refers to the number 150 in his book The Tipping Point.)

[Interconnected]

I’ve been looking for a good link to this paper from 1993. Although there is a wide variation around the magic number 150 it is a really interesting conjecture. [A Man with a Ph.D. – Richard Gayle’s Weblog]

Good to have a link to some empirical support for notion that certain group scales are hard-wired.

Social networking – the link is the thing…

DM Review – The Link is the Thing, Part 3
By Richard Hackathorn

A partial list of references mentioned in this three part series:

Valdis Krebs :: Post-Merger Integration, Scale-Free Networks, The Oracle of Bacon at Virginia, Small World Project – Columbia University, Norah Jones, Citations: Social Network Analysis: Methods and Applications – Wasserman, Faust (ResearchIndex), DM Review – Farming Web Resources for the Data Warehouse , The PageRank Citation Ranking: Bringing Order to the Web – Page, Brin, Motwani, Winograd (ResearchIndex), Pagerank Explained Correctly with Examples, Pagerank Explained. Google’s PageRank and how to make the most of it., SIENA, Associative Link Analysis resource site.

…Part 1 of this article (August 2003 issue of DM Review) reviews the work in network analysis of complex systems, particularly the recent research into the small-world (SW) property, aristocratic-egalitarian (A-E) distinction and tipping points. Part 2 (September 2003 issue of DM Review) applies these concepts to the business intelligence (BI) and data warehousing (DW) fields with a new methodology called Associative Link Analysis (ALA) by discussing the translation of typical warehouse schema into an associative graph form. This article, Part 3, the final in the series, describes several metrics for analyzing graphs, strategies and tactics based on the SW property, and implementation issues…

Additional reading on a few of the concepts introduced in this three part series:

“Small World Property”: Locality, Hierarchy, and Bidirectionality in the Web (ResearchIndex),
“Small World Architectures”: Multiple Scales in Small-World Networks (ResearchIndex),
“Tipping Points”: Tipping Points,
“ER Schema”: A Formal Framework for ER Schema Transformation – McBrien, Poulovassilis (ResearchIndex).

[judith meskill’s knowledge notes…]

Great collection of substantive resources on network analysis. I wish that more of the designers of services like Ryze, LinkedIn, and the like had read and absorbed these lessons before launching into software development. I see little evidence that they have and with the lemming like rush of VC money into this space, I’m betting on a mini-bubble popping in the not too distant future.

Welcome misbehaving.net

we're misbehavin'. I’m delighted to announce the debut of a new weblog on the topic of gender and technology: misbehaving.net We’ve got a really amazing group of women participating on this site: danah boyd Caterina Fake Meg Hourihan me (Liz Lawley) Dorothea Salo Halley Suitt Gina Trapani Jill Walker We all believe it’s important to begin changing the public perception of women in the context of technology, and that one of the best ways to do that is to make women’s accomplishments, writings, and contributions more public and visible. I hope you’ll add the new site to your blogroll and/or aggregator list!… [mamamusings]

From the site's description:

misbehaving.net is a weblog about women and technology. It's a celebration of women's contributions to computing; a place to spotlight women's contributions as well point out new opportunities and challenges for women in the computing field.

Since I already have about half the group posting here in my subscription list, I suspect this will be worth the attention. The RSS feed (RSS 1.0 format) is truncated, which wouldn't be my first choice, but better than no feed at all.

 

How Everyday Things Are Made

How Everyday Things Are Made.

How Everyday Things are Made: Spent the morning with my kids on this site. They loved it. Good example of learning with video/audio and limited interaction (“apply it” section). I'm reminded of how we are still in the early stages of elearning…and offerings will continue to be more sophisticated. My first exposure to the Web was a text only experience. Now, in a very short period of time, the browsing experience has become interactive, media-rich, and user-friendly (in many cases). We have the background of Web progression to direct our efforts in elearning…so it's safe to say that over the next five years, we'll see an exponential improvement in the quality of elearning materials.

[elearnspace blog]

For those times when you really want to do a factory tour and you don't have one handy.

Technology Review weblog

Technology Review launches weblog.

The folks at MIT Technology Review (to which I subscribe) have started a weblog, including posts from folks like Simson Garfinkel, who I've been reading for a long time (if you've never owned Simson's PGP book from O'Reilly, where have you been?)   In one of the first posts, Simson notes my recent switch to Mac OS X, writing: “The Mac is offering a really interesting niche to the technological elite.”  I actually just installed X11 on my Mac this weekend.  For fun.

My only polite request to the Technology Review folks would be to add an RSS feed and permalinks to the individual posts, but having tangled with content management systems too many times, I'm not going to get too preachy on how easy that might be, because maybe it isn't.

[Chad Dickerson]

Technology Review is one of the few print sources I both subscribe to and read regularly. A weblog from them should be well worth following. Let's hope the RSS feed follows soon.

Another new blogger without an RSS feed

Welcome another biz/tech blogger

Umair Haque is blogging from the UK at Bubble Generation. Among others, he's got interesting posts on the impact of RIAA policies on developing economies and cultures and why ibankers shouldn't be giving advice on tech venture strategy. Oh, and he thinks there's a bubble in social software. [Due Diligence]

Looks like some interesting material and good takes on a number of topics. No RSS feed I could find, so somebody let me know when one appears. Until then, I have better things to do than surf there in hopes there's something to see.

Here's my selfish rule for new and potentially interesting blogs I hear about. I make one visit. If, and only if, there is an RSS feed I will subscribe to it if the first visit seems promising. No RSS feed and I will probably never go back unless several of the weblogs in my subscriptions list point me there.