Khalid on #joiito pointed me to the following article.
It's an interesting article about how an email six degrees experiment shows we are no closer than when Milgram did his famous experiment in 1967. (Milgram did an experiment which resulted in the assertion that we are only six hops away from anyone else in the world.) I referred to Milgram's famous experiment in my Emergent Democracy paper. When the paper was being reviewed by Shumpei Kumon, he referred me to Six Degrees by Duncan J. Watts and pointed out to me that Watts writes about Judith Kleinfeld who found that Milgram's experiment was flawed. I removed the reference in my paper. Milgram's six degrees experiment is so widely referenced that it has become almost an urban legend, but it DID NOT show that the world was connected by six degrees, it just got us thinking about it. I think the phenomenon is real and the "small-world problem" is a very interesting field, but people should stop quoting the Milgram study as fact. The email experiment referred to in the article is being conducted by Duncan Watts as well and he has a web page with more info.New ScientistEmail experiment confirms six degrees of separation
Despite enabling almost instantaneous global communication, email appears not to have made the world a more close-knit community.
Duncan WattsThe Psychologist Judith Kleinfeld stumbled onto what nows seems like a classic instance of such misplaced faith while she was teaching her undergraduate psychology class. [...] Remember that Milgram started his chains with roughly three hundred people, all of whom were trying to get their letters to a single target in Boston. The story everyone tells has the three hundred people living in Omaha, but a closer look reveals that one hundred actually lived in Boston! Furthermore, of the almost two hundred in Nebraska, only one-half were randomly selected. [...] The other half were blue-chip stock investors, and the target, of course, was a stockbroker. The famous six degrees is an average over these three populations, and as you might expect, the number of degrees varies quite a bit between them, with the Boston natives and the stock investors managing to complete chains more successfully and with fewer links than the random Nebraska sample.
Remember also that the surprising finding about the small-world claim is that anyone can reach anyone--not just people in the same town or people with strong common interests, but anyone anywhere. So really the only population that satisfied, even remotely, the conditions of the hypothesis as it is usually stated (even by Milgram himself) was the ninety-six people picked out of the Nebraska mailing list. At this point the numbers starts to get disturbingly small: of ninety-six starting letters in that population, only eighteen reach the target.