The enterprise of fact-checking continues to proliferate throughout the US news media to an unprecedented degree. While many welcome this trend, others question the effectiveness of fact-checking and some have even begun to push back. A common critique is that factchecking has failed to eradicate deceptive and misleading claims by politicians and is therefore ineffective. Others have concerns about the presence of bias in fact-checking work. This report draws on evidence from social science as well as recent interviews with reporters, fact-checkers, critics, and political figures to consider these issues and how they played out during the 2012 campaign. Because fact-checking is relatively young, robust metrics to empirically measure its effectiveness are still being established. Hence, a recurring theme in this report is the difficulty in definitively distinguishing the effects of fact-checking.

A broad conceptualization of fact-checking suggests it can influence three constituencies: the public, political operatives, and journalists. Fact-checkers are outspoken that their primary objective is to inform the public. However, fact-checkers also acknowledge other audiences, though sometimes implicitly. Thinking about fact-checking as a multidimensional initiative assists in understanding the many ways in which it could influence politics. First, it may help to inform the public. Fact-checkers have acquired a vast audience and they may help to make them better-informed. For instance, a recent study by the Annenberg Public Policy Center finds that people who rely on fact-checking are more informed about politics than are those who do not. 1 In addition, fact-checking may have helped spur some political operatives to make more accurate claims. However, others have resisted fact-checking and even pushed