Exit Polls: More Questions

Exit Polls Legacy blog posts

Dave M asks:

You say that they poll randomly through the day and when the final precinct vote (not survey) counts are available, they get incorporated. If exit poll interpretation isn’t done until the voting is done, then why use the survey (a limited sample with the inherent sampling errors) at all? Why not just use the official vote tallies?

Good question. The exit poll incorporates hard data on turnout first then data on actual voting as it becomes available precinct by precinct. My knowledge on the specific procedures they use is weak, but the interviewer is responsible for getting hard data on turnout, especially at the end of the day (either from their own tally, from the precinct officials or both). This turnout data is critical to weighting the end-of-day poll. Then as the precinct vote becomes available, they integrate the two to make the poll more and more accurate as the night wears on. Once the complete results are known, the exit polls are weighted to match the vote.

Mean Dean asks:

Do incidence rates play any significant part in the quality of data? If so, which way? I’d suspect if I was on my way (back) to work, or rushing home for dinner afterwards, or toting copious kiddage I’d find myself declining an exit poll as well.

The one thing exits polls can do is track the gender, race and (approximate) age of those who refuse to participate and adjust the resulting sample to correct for any flaw. Because the exit poll result can be compared to the actual vote in each of hundreds of individual precincts, methodologists can check whether the error rate increases in precincts with lower rates of response. This short answer is higher response rates do not lead to higher error in exit polls.

One last link recommendation: the folks who conduct the exit polls have a great guide on things to look for tonight (hat tip: Andrew Sullivan)

Now, time to watch this thing…I’ll post more later

Mark Blumenthal

Mark Blumenthal is political pollster with deep and varied experience across survey research, campaigns, and media. The original "Mystery Pollster" and co-creator of Pollster.com, he explains complex concepts to a multitude of audiences and how data informs politics and decision-making. A researcher and consultant who crafts effective questions and identifies innovative solutions to deliver results. An award winning political journalist who brings insights and crafts compelling narratives from chaotic data.