The PresidentialWatch08 map is composed of the 533 most visible and influential websites and blogs – out of a complete dataset of over 4000 sites – using Linkfluence™’s proprietary crawl technology.

The map includes both social media and mainstream media outlets. The sites are divided into four different categories, or communities (manually labelled):

• Conservative
• Independent
• Infopit
• Progressive

Infopit are conversation starters, they can set the agenda. Most of them are mainstream media but a growing part is composed by social media.

In terms of methodology, we initiated the process by focusing on a set of a few hundred websites and blogs well-recognized by search engines and other sites related to US politics. Then, we collected the URLs of all sites located just one click away from our initial set – which amounted to tens of thousands of websites.

Why was this step important? Because when it comes to networks – and the web is one giant network – there’s a rule that says that what’s similar to a given node in terms of content will stand close to this node in terms of location. Working with a set of websites large enough, one can collect all the other important websites dealing with the same topics using the “one click removed” idea.

Thanks to a series of metrics, both topology-related (i.e. how many sites link to a particular site) and semantics-related (i.e. are the words used of political nature), we were able to single out over 4,000 websites that constitute the core of the US political webosphere. From these, we extracted the most link-relevant 533 sites.