Danny Sullivan posted a thread at SEW forums named News Search & Biases, where he points to an article written at OJR.org named Balancing Act: How News Portals Serve Up Political Stories. This blew my mind.
The article discusses how Google News seems to be favoring the conservative papers over the more left-wing, liberal papers. The logic is as follows: Do a search at Google News on Kerry and your likely to see articles that are in opposition to Kerry. Now do a search on Bush at Google News and you will find news that favors Bush. How is it that Google News, an algorithmic search technology, can be a conservative over a liberal?
The article gives an excellent theory as to the answer to this question. They quote Ethan Zuckerman, former vice president of Tripod.com and now a fellow at Harvard's Berkman Center for Internet and Society, who offers a possible answer to this question. Basically, he says that the main stream (conservative) papers often, when discussing Kerry, put "Kerry" in the title of the article. Whereas, the liberal papers do not. In addition, the liberal papers often use Kerry's full name in the article content and if you do a search on John Kerry as opposed to just Kerry in Google News, you will find more liberal papers discussing Kerry.