There is a brand new way to assess the content of social media — blogs, social network sites, video-sharing sites and the like.

Our colleagues at the Pew Research Center’s Project for Excellence in Journalism have developed a New Media Index that analyzes the major news topics that are covered by social media participants.

The index draws on the tens of millions of weekly posts and links that are captured by Technorati and Icerocket. The Project then does its own analysis of the content of the news stories that draw the most links from social media sites.

The extra-added bonus is that PEJ each week will compare the material that appears in the New Media Index to its content analysis of the material that appears in its News Coverage Index, a rich content analysis of the stories covered by traditional news organizations.

My strong hunch is that this weekly comparison will provide lots of evidence that bloggers and other social media participants constitute a “fifth estate,” the memorable and extremely useful insight of William Dutton, the Director of the Oxford Internet Institute.

Here’s how PEJ explains its motive for indexing the top topics that bloggers and other social media participants link to and discuss:

“PEJ is launching the New Media Index as a companion to its weekly News Coverage Index. Blogs and other new media are an important part of creating today’s news information narrative and in shaping the way Americans interact with the news. The expansion of online blogs and other social media sites has allowed news consumers and others outside the mainstream press to have more of a role in agenda setting, dissemination and interpretation. PEJ wanted to find out what subjects in the national news the online sites focus on, and how that compared with the narrative in the traditional press.”

The latest survey from the Pew Internet Project that was completed on December 20 shows that 11% of American adults are bloggers, and 32% are blog readers.