Tuesday, November 11, 2014

Fact-checking while blind, with PolitiMath

One of the things we would predict from biased journalists is a forgiving eye for claims for which the journalist sympathizes.

Case in point?

A Nov. 11, 2014 fact check from PolitiFact's Louis Jacobson and intern Nai Issa gives a "True" rating to a Facebook meme claiming Congress has 11 percent approval while in 2014 96.4 percent of incumbents successfully defended their seats.

PolitiFact found the claim about congressional approval was off by about 20 percent and the one about the percentage of incumbents was off by a maximum of 1.5 percent (percentage error calculations ours). So, in terms of PolitiMath the average error for the two claims was 10.75 percent yet PolitiFact ruled the claim "True." The ruling means the 11 percent average error is insignificant in PolitiFact's sight.

Aside from the PolitiMath angle, we were intrigued by the precision of the Facebook meme. Why 96.4 percent and not an approximate number by 96 or 97? And why, given that PolitiFact often excoriates its subjects for faulty methods, wasn't PolitiFact curious about the fake precision of the meme?

Even if PolitiFact wasn't curious, we were. We looked at the picture conveying the meme and saw the explanation in the lower right-hand corner.

Red highlights scrawled by the PolitiFact Bias team. Image from PolitiFact.com

It reads: "Based on 420 incumbents who ran, 405 of which kept their seats in Congress."

PolitiFact counted 415 House and Senate incumbents, counting three who lost primary elections. Not counting undecided races involving Democrats Mark Begich and Mary Landrieu, incumbents held 396 seats.

So the numbers are wrong, using PolitiFact's count as the standard of accuracy, but PolitiFact says the meme is true.

It was fact-checked, after all.

No comments:

Post a Comment