Social-networking sites are important Petri dishes. By studying the social Web, researchers are learning a lot about how people interact - not just about how they do so now and online but about human interaction in general. In fact, research in social-networking sites "may be more accurate than personal information offered elsewhere online, such as chat room profiles, because [it's] based in real-world relationships that originate in confined communities like campuses," reports the New York Times, referring to a UCLA- and Harvard-based study of 1,700 Facebook users in the junior class of one northeastern US college. One of the things they're looking at: "weak ties," those between, say, two classmates or people who meet at a big party. "Weak ties are significant, scholars say, because they are likely to provide people with new perspectives and opportunities that they might not get from close friends and family." According to the Times, "social scientists at Indiana, Northwestern, Pennsylvania State, Tufts, the University of Texas and other institutions are mining Facebook to test traditional theories in their fields about relationships, identity, self-esteem, popularity, collective action, race and political engagement. The Washington Post recently ran a gossipy piece about the fledgling social-media research community which got some reaction in the academic blogosphere (e.g., ), but it does name a number of the individual researchers and projects working on the social Web right now. Back to the Harvard-UCLA project: An important concept they're exploring is "triadic closure," "first put forth by the pioneering German sociologist Georg Simmel … whether one’s friends are also friends of one another. If this seems trivial, consider that a study in 2004 in The American Journal of Public Health suggested that adolescent girls who are socially isolated and whose friends are not friends with one another experienced more suicidal thoughts."