The shift of communication to the internet, in particular to email, weblogs (blogs), and online communities, presents an opportunity to study the information dynamics of social networks on a large scale. Blogs, now numbering in the millions, are web pages updated using blogging software that makes it easy for authors to share new content online in the form of time-stamped posts.

One can track how a piece of information spreads by observing when it appears on different blogs. The exact route the information takes is not obvious, since most blog authors will not explicitly identify the source of the information when they write about it. Likely routes can be inferred, however, by analyzing timing information, blogs' past entries, and the explicit network of blogs linking to one another through blogrolls or posts. While one can gain insights from observing how information passes from one individual to another, one can also analyze networks to see how easily one can actively navigate them to locate needed information or individuals.

One test of the navigability of a network is the classic small world experiment, where subjects attempt to reach a target individual through their chain of acquaintances. Examining an email network within an organization reveals how individuals are capable of routing messages locally, even though their knowledge of the organization's global social network is limited.