We have all heard the recent discussion about “fake news” and worries that the integrity of news is under attack in many places on the web and social media.We also have learned, from our usage metrics and experience, that there’s a vast appetite out there for stories that hold politicians and public figures accountable for their words.At the AP, we’ve always had the mission of “bringing truth to the world.” Fact-checking has been an important part of that, and one reason that we are among the trusted organizations partnering with Facebook to identify and debunk false information that’s gaining notice on that social platform, an effort showing positive effects already.So it is a good time to review and define our general fact-checking policies and practices.Here is a rundown of what we fact-check and why.There are two general categories:—We push back on political spin, exaggeration and falsehoods.This is how the traditional AP Fact Check began, principally in Washington, looking at speeches by the president, political candidates and other politicians and officials. State and international bureaus have done fact checks too on speeches by other leaders, including at the United Nations.—We debunk false reporting and the growing phenomenon of deliberately “fake news.”We want to identify and debunk trending stories of all kinds, whether in text, photos or videos, that are fictional, contrived, twisted or otherwise patently false yet likely to be mistaken for truth by unwary news consumers. An example would be the widely circulated story last year that Pope Francis had endorsed Donald Trump’s candidacy for president. No such endorsement had occurred, yet many people believed it.Note: The two genres of fact-check stories are distinguished by the editor’s notes that go with them:— The traditional fact checks carry this note in the Publishable Eds. Note field: EDITOR’S NOTE: A look at the veracity of claims by political figures.— The “fake news” stories carry this note at the bottom of the story below a dash line: This story is part of an ongoing Associated Press effort to fact-check claims in suspected false news stories.Some other key rules and guidelines:Be sure we are right. Never state in a fact check anything of which we’re not certain.Prioritize items with relevance and importance. We can’t check every falsehood. Focus on things that matter.Keep items short. The lead should present the assertion that’s being checked, and quickly state what’s wrong with it. Because it is words being examined, we need exact quotes. That should be followed by our presentation of the facts, backed by appropriate citations and attribution.Stick to checking facts, rather than opinion. A person’s personal tastes and preferences might lie outside the mainstream, but as opinions they are not a topic for a fact check.Our ruling doesn’t have to be black and white. Statements can fall along a wide range of accuracy, and we don’t use a rigid rating scale to make our judgments. A statement can be false, exaggerated, a stretch, a selective use of data, partly or mostly true. We use the most apt description that’s supported by what we know.Make use of the AP’s in-house expertise. Fact checks are reported stories. AP’s own beat reporters, from politics and government to science, sports and medicine, are among our best resources to make sure our fact checks are solid.