(Host) When polls close across Vermont about an hour from now, the Associated Press will begin releasing data from its exit polling.

The AP exit polls are typically the first to project the winners of major races, like today's presidential primary.

AP Polling Director Mike Mokrzycki covers the polls in Vermont.

Speaking today on Vermont Edition, he said there's a second, more valuable purpose to exit polling.

(Mokrzycki) "We also use the surveys to explain why the election turned out the way it did - why the winner won, why the loser lost. And in my mind, that's where exit polls are especially invaluable because there's no other way to get that information. We need a survey to be able to find out which demographic groups favored a certain candidate, or which issues or candidates' qualities or other factors were decisive in the outcome."

(Host) The Associated Press collects data in 20 precincts across the state.

At each site the AP aims to conduct surveys with 100 voters.

And there's an ‘organized randomness' to selecting voters for exit polling.

(Mokrzycki) "The interviewers are instructed to approach, say, every fifth person as they leave the voting booth. What we do not want is for interviewers to pick only people who look like they may be friendly and cooperative because that may introduce bias into the sample."

(Host) Mokrzycki says the AP will not release polling data in any state before that state's polls are closed.

The policy means last-minute voters won't be influenced by early predictions of who will win a given race.