Social Networks have received a great deal of attention lately with the increasing popularity of websites such as MySpace, Facebook, and LinkedIn. But research using social network analysis (or what is sometimes called Sociometry) dates back at least to the "small World" experiments conducted by Stanley Milgram in the 60's. In these studies, participants passed messages through their acquaintances and the networks of these social exchanges were mapped and measured for the strength of their connections, or ties. Although problematic, these experiments provided the genesis of modern social network theory and research linking social connections to power, capitol, and influence. Since the early 70's Social Network Theory has been applied to topics as diverse as:

• International relations and trade
• Corporate connectivity
• Community cohesion and disenfranchisement
• Public opinion and marketing
• Individual reputations within groups
• Similarities between human and computer networks
• Online communities
• Terrorist cells

For journalists, social networks provide not only data for investigative reporting, but also new ways of finding experts, tracking trends, and searching the web (with a little help from your friends). This month's column provides links to resources on Social Network Analysis including tutorials, software tools, social networking sites, and search engines that leverage social referrals.

Background and tutorials

Introduction to social network methods.
Written by Robert A. Hanneman and Mark Riddle. This is an on-line textbook that provides a fairly comprehensive introduction to the analysis of social networks. The focus is on the application of formal, mathematical methods of analysis.

Managerial Network Analysis
Professor and Chair of Organizational Studies at Boston College, Steve Borgatti has created this website which explores the use of network analysis in management.

Social Network Analysis Helps Maximize Collective Smarts
This article By Susannah Patton appeared in the online version of CIO magazine.

Connecting the Dots -- Tracking Two Identified Terrorists
Written by Valdis Krebs this article describes how a terrorist leader was found by using social network analysis. It goes through the steps that were taken and shows how to perform a social network analysis.

How the NSA Does "Social Network Analysis"
This article, by Alexander Dryerin appeared in SLATE magazine online. It reveals how the National Security Agency uses social network analysis and points to Krebs as an example. Short introduction to how social network analysis is done, as well as a discussion of its effects.

Tools and software

Sociograms
Examples of different ways of graphically depicting the connections between people.

InFlow (by Orgnet.com)
This software was designed originally to map social networks within organizations and businesses.

Associations, organizations, experts

The International Network for Social Network Analysis is the professional association for researchers interested in social network analysis. INSA was founded in 1978 by Dr. Barry Wellman, (see below). The site has information about experts, publications, educational resources, programs, list of upcoming conferences, events etc.

Albert-Laszlo Barabasi
Barabasi's 2004 book: Linked: How Everything Is Connected to Everything Else, describes how networks (of friends, websites, airports, commerce, proteins, etc) share the same mathematical properties.

Social search engines

Based on the notion that, under the right circumstances, crowds make reasonably sound and consistent choices. (see: The Wisdom Of Crowds by James Surowiecki), Social Search Engines leverage the opinions of the community to index resources and make recommendations. Also sometimes known as folksononomic tagging, social search can also be operationalized in sites such as Yahoo answers, and the Virtual reference desk. At its most automatic, its exemplified by amazon's referral mechanism: "People who bought this book also bought___"

StumbleUpon uses ratings by users to form collaborative opinions on website quality. When you search, you see pages which friends and like-minded users have recommended.

Digg Everything on Digg is submitted by members. After content is submitted, other Digg members read the submission and rate what they like best. Members can also track the activities, ratings and content submissions of their friends.