In Chapter 2 of the Signal and the Noise, a book by Nate Silver (@NateSilver538), he talks about how David Wasserman (@Redistrict) –U.S. House editor of Cook Political Report— interviews House candidates before elections but the interviews do not affect the predictions for most candidates. At first glance, these interviews may seem unnecessary, but Wasserman uses them to spot red flags about candidates; which helps him account for unlikely events and improve the accuracy of the predictions even more.
Nate Silver is the editor-in-chief of FiveThirtyEight,