Aggregating political polls

A colleague and I were talking about how fun it would be to be teaching a statistics class during this presidential election season—especially talking about the political polling process.

Recently I came across, an interesting website that takes published political polls, applies its own analysis to them, and puts out its own predictions. (It is named after the number of electors in the electoral college system.) For example, they

assign each poll a weighting based on that pollster’s historical track record, the poll’s sample size, and the recentness of the poll. More reliable polls are weighted more heavily in our averages. was created by Nate Silver who created PECOTA a successful method for predicting player statistics in baseball. became famous during the primary season when it out-predicted the experts when Clinton barely won Indiana and Barack Obama won North Carolina decisively.