“There are two ways to think about connectivity on Twitter: People “follow” each other (a fairly passive form of interaction), but they also actively engage other people through retweets or direct conversation (mentioning another user’s handle). This first kind of relationship is akin to subscribing to magazines. We may know, for instance, that you get Cat Fancy, TIME, and The Atlantic. But that information tells us nothing about which articles you actually read, or which magazines merely decorate your toilet.

“In reality on Twitter, even though you may be following a lot of people, you’re probably paying attention more to some than others. But there’s no way of recording that,” Leetaru says. “What we can do is say ‘well, here are the people you’re talking to. Here are the people you thought were interesting enough to retweet.’”