Even very simple text classification can get you somewhere. Last year a couple of economists, Matthew Gentzkow and Jesse Shapiro, published a wonderful paper in

Even very simple text classification can get you somewhere. Last year a couple of economists, Matthew Gentzkow and Jesse Shapiro, published a wonderful paper in which they did something similar. Take a look at it: http://home.uchicago.edu/~jmshapir/biasmeas052507_formatted.pdf http://home.uchicago.edu/~jmshapir/biasmeas052507_formatted.... "To measure news slant, we examine the set of all phrases used by members of Congress in the 2005 Congressional Record, and identify those that are used much more frequently by one party than by another. We then index newspapers by the extent to which the use of politically charged phrases in their news coverage resembles the use of the same phrases in the speech of a congressional Democrat or Republican." They then go on to compare their index of politically-slanted language in newspapers to the politics of the newspapers' readers, and conclude that newspaper bias is driven more by readers wanting their own prejudices confirmed than by the politics of the newspaper owners. It's a really great piece of work: worth reading in full if you have any interest in text classification politics.