Understanding election night exit polls: A guide to how they work

An exit poll is a survey administered to voters as they leave their polling place. Unlike pre-election polls that predict voter intent, exit polls reflect the actual views of those who have already voted.

This year’s midterm election exit polls are being conducted by SSRS, a survey and market research firm, on behalf of a consortium of news organizations including NBC News, ABC News, The Associated Press, CBS News, CNN, Fox News, and MS NOW. NBC News independently analyzes and reports on the data.

The national exit poll asks voters for whom they voted for in House races, and in many states, also inquires about Senate and gubernatorial choices. Questions also explore voter priorities, such as the most important issue facing the country, and gather demographic information like age, gender, race, and education level. This data helps illustrate how different groups voted and what influenced their decisions.

Over 450 polling locations in 15 Senate battleground states will have interviewers stationed to administer paper questionnaires with approximately 25 questions. A pre-election survey, conducted via mail, telephone, text, and online, captures the views of voters regardless of how they vote.

Interviewers follow up with respondents to confirm their participation and voting choices. Polls are available in both English and Spanish. Interviewers are instructed to approach every third or fifth person leaving the polling place, from the time polls open until they close, and report results three times daily.

Exit polls are anonymous; voters fill out questionnaires themselves and deposit them in boxes, and interviews conducted remotely do not retain personal information.

In addition to a national poll, exit polls will be conducted in 45 states with consequential Senate and governor’s races. The national sample will include over 75,000 voters, with 15 states having at least 30 randomly sampled voting locations. Sample sizes in Arizona, California, Florida, Georgia, Iowa, Maine, Michigan, Minnesota, Nebraska, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Texas, and Wisconsin will be approximately 4,000 voters. Alaska’s sample size will be around 3,000, and other states will range from 500 to 3,000 voters.

NBC News’ Decision Desk utilizes exit poll data to project race outcomes, but primarily uses the data to provide insight into voter motivations and feelings about the country. NBC News will not report exit poll results before 5 p.m. ET on election night, and will refrain from reporting results that might indicate an outcome until all polls are scheduled to close.