BOB GARFIELD:  This week, Twitter went dark for a half an hour and, predictably, a cyber freakout ensued. As Wired Magazine put it, “Twitter is no longer simply a place where people come to make jokes and drop quickie status updates. It's practically infrastructure, a core component of the global communication system.” With more than 240 million active users engaged in activities ranging from abetting revolution to reporting tornadoes to photographing dessert, Twitter’s cultural impact cannot be denied. But can we use it to chart how we actually communicate, not just with our own cohorts but with the world outside?

The Pew Research Center set out to map the informational ecosystem of Twitter, and Lee Rainie, Director of the Pew’s  Internet and American Life Project, says it is a social scientist’s dream.

LEE RAINIE:  Think of this work as equivalent to 19th-century biologists going up the Amazon or landing on a new island and literally being able to see things that had existed for a while but had never been seen and documented in this particular way.

BOB GARFIELD:  By analyzing thousands of politically inclined conversations on Twitter, Pew created a series of maps, with mountains, valleys and islands distributed over six e-continents, each representing a different conversational structure. The first is familiar, a conversation prompting the emergence of two highly polarized crowds.

LEE RAINIE:  It really has the feel of sort of high school social structures, where they don't talk to each other, but they definitely talk about each other.

BOB GARFIELD:  Another map depicts a diffused crowd, like shoppers in a designer clothing store, all talking about the same brands but not talking to each other. Pew found six structures in all. A third shows how news stories tend to prompt relatedness niche conversations, like the spokes on a wheel. We’ll let Rainie pick it up from there.

LEE RAINIE:  Another structure - we did a map of a very prominent commentator, Paul Krugman, that shows that every time he writes a column there are lots of people who are paying attention and then talking about what he says, but they’re not necessarily talking to each other about it. They're just passing it along to their tribes, to their followers, so it looks like a starburst.

And a final one is the opposite of that, where people are working from the outside in to a centralized source. It's often the case that companies are now sort of following their brands and their reputations online and they're trying to respond to customer commentary, sometimes customer complaints about what they're doing. So the spokes go in the opposite direction.

BOB GARFIELD:  “Oreos are so great with milk, Verizon really sucks.”

LEE RAINIE:  That’s pretty much the flavor it.

BOB GARFIELD:  We have often wrung our hands institutionally about the polarization of news and, and political thought and looked to social media, like Twitter, as a way to break down those barriers. So far, you're not seeing evidence that we are being more thoughtful, more open minded, more catholic in our tastes?

LEE RAINIE:  Certainly, the maps that we produced for polarized conversations show what you’ve been worried about. There is very little interaction between the clusters. There's actually very little similar information. They literally are relying on different foundational information sources as the basis of their conversation. And one of the striking things that we see in American political discourse is that those in the liberal cluster are relying, in many cases, on traditional mainstream news sources. In the conservative cluster, there’s sort of a parallel conservative media universe now that is becoming enormously potent and driving those conversations.

However, researchers in Korea who have used this tool have seen a seventh kind of structure in conversations that looks more like a barbell. So there are definitely too big clusters of folks who are talking about their side of the story, but between the two big clusters there actually is a pretty thick band of social network overlap, of information similarities. And so, it might be the case that it's just certain issues in America do show this very deeply polarized echo chamber kind of structure. Other conversations in other kinds of locales don't have exactly that same worrisome polarization to it.

BOB GARFIELD:  I guess what I’m asking you ultimately, Lee, is as you look at the data, do you find yourself welling up with tears of hope and inspiration or of - you know, despair?

LEE RAINIE:  Well, the researcher in me is crying for joy. We are able to look at dimensions of human behavior that were traditionally hard to explore, certainly hard to give contours to in maps like this. Think of us as being astronomers who have gotten a much more powerful telescope to look deeper into the heavens. We’re just happy to see the stuff, so this is the beginning of a general exploration of human relations that we haven't had before.

BOB GARFIELD:  That's the scientist in you. Tell me about the citizen in you.

LEE RAINIE:  That cuts in both directions. There are things that do make you feel like new kinds of connections are being built, new kinds of relationships are being nurtured. However, you can see lots of the ways that people are miserable to each other. It's not a uniformly good or a uniformly bad story but, from a research perspective, knowing all of that is an enormous advantage.

BOB GARFIELD:  Well, that’s reasonably optimistic. I’ll tell you what, with your permission, you cling to that and I’ll go for the despair. Lee, thank you very much.

LEE RAINIE:  Thanks, Bob.

BOB GARFIELD:  Lee Rainie is co-author of the report, “Mapping Twitter Topic Networks” and he’s director of Pew’s Internet and American Life Project.