"Homophily is a fancy word for the human equivalent of “birds of a feather flock together.” That is, our tendency to associate and bond with people we have stuff in common with — language, culture, race, class, work, interests, life circumstances, etc." (http://www.contentious.com/2008/04/20/breaking-out-of-the-echo-chamber/)
"We know so little about one another, and what we do know is generally so wrong, that our first instinct is to try to shut each other off. …We have to work a whole lot harder. We can’t just assume that being connected [via the net] solves these problems. If you let us work it out on our own, we tend to reinforce our own prejudices and stereotypes.
“If you look at sites like Digg and Reddit, these are sites that promised the future of journalism, where we would all get together and decide what’s important. …But that begs the question: Who’s ‘we?’ If you’re getting your news from these sites, you’re getting a fairly focused, tech-heavy view of the world. You start to fall victim to homophily. It’s a basic human trait, but it’s probably worth fighting.
“Cass Sunstein, an amazing legal scholar, says that one of the dangers of the internet is that we’re only hearing like voices, and that makes us more polarized. Homophily can make you really, really dumb. What’s incredible about the net is we have this opportunity to hear more voices than ever. But the tools we tend to build to it have us listening to the same voices again and again.
“Search in the future needs to lead us to people, to places, to voices. My hope is that in the future we get over homophily and we start looking for really productive serendipity — the sort of serendipity when you go to that shelf in the library and you think you know the book that you’re looking for, but you actually find the book you’re really looking for within 2-3 shelves of it. You think you’re looking for info on the US elections, but you end up finding info on how the Jamaicans are viewing the US elections. You think you’re looking for info on network security and you en d up finding information on why Pakistan is so afraid of YouTube.
“Encountering new ideas isn’t a supply problem in today’s internet — it’s a demand problem. There’s a near infinity of people unlike you creating content and putting it online for you to encounter. But it’s entirely possible that you’ll never encounter it if you don’t actively look for it… or unless the systems you use to find ideas start forcing you outside your usual orbits into new territories. Don’t fear the serendipity.” (http://www.contentious.com/2008/04/20/breaking-out-of-the-echo-chamber/)