Poliltifact.com's "Truth-o-Meter"

Politifact.com’s “Truth-o-Meter,” with its iconic “Pants on Fire” rating for baseless statements, is one of the more recognizable examples of political fact-checking. Fact-checking has emerged as a powerful and more prevalent tool in American journalism.

It’s hard to believe, but the idea that reporters should debunk deceptive claims by politicians — now called “political fact-checking” — is fairly new in American journalism.

Any respectable news outlet tries to verify facts it reports, and publishes corrections when mistakes happen. The first fact-checking departments appeared at national magazines, like Time, nearly a century ago.

But for most of the 20th century, reporters were reluctant to directly challenge official claims, leaving that to other politicians. Wisconsin Sen. Joe McCarthy took advantage of that to get his wild accusations into print.

In recent decades, though, many newsrooms shifted away from that “stenographic” approach. Especially since the 2004 election, journalists have made debunking false claims a political coverage staple, following the example set by nonpartisan online sites like FactCheck.org, PolitiFact, and the Washington Post’s Fact Checker.

I study how journalism is adapting to the digital world. The rise of political fact checking shows journalists using new tools to answer decades-old complaints about “false balance” in the news — and to combat rampant online misinformation.

It also shows that good ideas are contagious. As it took hold here, political fact checking went global. More than 100 fact-checking operations now exist in almost 50 countries, from Chile to Canada and from Sweden to South Africa.

Fact checking is headed into the classroom, too. Last fall, my colleague Mike Wagner taught a new fact-checking class for undergraduates that we developed with support from the Ira and Eneva Reilly Baldwin Wisconsin Idea Endowment.

The best news is that our students loved the chance to hold elected officials accountable for the things they say.