I dont know what the fuck this site is but it seems relevant,
"
Frequently Asked Questions About the NEP Exit Poll
What is the National Election Pool (NEP)?
The National Election Pool is a consortium of ABC News, Associated Press, CBS News, CNN, Fox News and NBC News. It was formed in 2003 in order to provide information on Election Night about the vote count, election analysis and election projections. NEP contracted with Edison Research to make projections and provide Exit Poll analysis. In addition, the NEP retained the Associated Press to conduct a tabulation of the vote throughout the country.
What does Edison Research provide to the NEP?
Edison Research conducts statewide Exit Polls throughout the country as well as a National survey. In addition, Edison collects the vote count in a sample of precincts in each state. Edison provides Exit Poll analysis and projections for President, U.S. Senate, Governor as well as selected U.S. House, and state referenda and initiatives.
What is an Exit Poll?
Exit Polls are interviews with voters after they have cast their votes at their polling places. A sample of precincts is scientifically selected to collectively represent a state, or for the national Exit Poll, the nation. An interviewer gives every nth voter exiting the polling place a questionnaire to complete. There are questions about demographics such as gender, age, race, and issues related to the person’s vote choice in different contests. Participation is voluntary and anonymous. The interviewing starts when the polls open and continue throughout the day until about an hour before the polls close.
Who decides what questions to ask on the Exit Poll?
All questions asked on state and national questionnaires are prepared by the six members of the National Election Pool.
How many polling places will be in your sample?
Sample sizes vary from state to state.
How do you select sample precincts?
Precincts are selected as a stratified probability sample of each state. The purpose of stratification is to group together precincts with similar vote characteristics. A recent past election is used to identify all precincts as they existed for that election. The total vote in each precinct and the partisan division of the vote from this past race are used for the stratification. In addition, counties are used for stratifying the precincts. The total vote also is used to determine the probability of selection. Each voter in a state has approximately the same chance of being selected in the sample.
Who makes projections of the winning candidates?
Projections are made by Edison and transmitted to each of the NEP members and subscribing news organizations. Each of the members has its own analysts who review the Exit Poll results and the tabulated data as it is collected. Each news organization makes its own decision about what to report to the public. All decisions are made after careful review by the analysts and are not automatic decisions made by a computer.
How are projections of winners made?
Projections of a winning candidate are based on models that use votes from three different sources — Exit Poll interviews with voters, vote returns as reported by election officials from the sample precincts, and tabulations of votes by county. The models make estimates from all these vote reports. The models also indicate the likely error in the estimates. The best model estimate may be used to make a projection if it passes a series of tests.
When will projections be made?
Projections of a winning candidate are only made after all the polls in a state are closed and when the best model estimates show a clear winner. There will be no projections before the last polls in a state are closed."
p2012.org/chrneday/edisonfaq.html
archive.is/aTZ4D