How do fact-checkers work? What's the trickiest aspect of reporting on political polls? Best new tools for following the trail of campaign cash? These were some of the questions addressed at a National Press Foundation briefing for journalists. PolitiFact editor Angie Drobnik Holan and Washington Post fact-checker Glenn Kessler joined us for a revealing 45-minute webinar about what they do. Key points: * The toughest part of a check is ascribing a rating. * Fact-checkers always check with the source of the statement or information; they like strong data-driven government websites such as; but they also use Google, at least to get started. * Often, the specific question is a launch-pad for a deep dive into the issue. * Local reporters need to be much more skeptical about statements from campaigns and candidates.