• Finally, does the statement concern a matter of public importance? Politicians’ personal lives are not irrelevant, but it’s hard to see how Paul Ryan’s exaggeration of his abilities as a runner helps anyone assess his fitness for the vice presidency.

As factchecking moves closer to the journalistic mainstream, it’s important that journalists are careful in what they label as “factchecks” and what statements they choose to scrutinize. Otherwise, the media could dilute and devalue a practice that should be an important part of campaign coverage.

Brendan Nyhan is an assistant professor of government at Dartmouth College. He blogs at brendan-nyhan.com and tweets @BrendanNyhan.