The Pew Research Center for the People & the Press is out with a report about "What Americans Know." Here's the AP recap.

"There are substantial differences in the knowledge levels of the audiences for different news outlets. However, there is no clear connection between news formats and what audiences know," the report states. "Well-informed audiences come from cable (Daily Show/Colbert Report, O'Reilly Factor), the internet (especially major newspaper websites), broadcast TV (NewsHour with Jim Lehrer) and radio (NPR, Rush Limbaugh's program). The less informed audiences also frequent a mix of formats: broadcast television (network morning news shows, local news), cable (Fox News Channel), and the internet (online blogs where people discuss news events)."

Here's the rest...