"Tim Groseclose, a professor of political science at UCLA, has made an earnest and impressive effort to address the central problem in deciding whether there is systematic media bias: finding an objective way of measuring bias, both an individual's and news outlet's. The first task is done by assigning to any politician, news outlet, or oneself a Political Quotient (P.Q.) based on whether you agree, disagree, or have no opinion on a policy question. The questions are those formulated by Americans for Democratic Action (ADA) to rank members of Congress. ...P.S. Michael LaCour, "a Ph.D. candidate in political science at UCLA", posts on A Balanced News Diet After All?
"To gauge the bias of the mass media, Groseclose develops another measure, the Slant Quotient (S.Q.). This is a number that shows how often a news outlet cites one or more of some 200 think tanks. ..."
--James Q. Wilson, Measuring the Slant, review of Left Turn: How Liberal Media Bias Distorts the American Mind, by Tim Groseclose
"Political scientists and journalists have concluded that individuals are motivated to select media sources that match their own political views and avoid media sources that challenge their political views. However, an analysis of individuals’ actual media exposure patterns lead to conclusions about selective exposure quite different from previous research based on self-reported media exposure."(Via W.W. at Democracy in America)