How to tell if a political poll is legitimate, UTSA researcher explains

Political polls are everywhere, and after last week’s revelation that one of them was fake, allegedly a social experiment, voters may be wondering how to tell which numbers to trust.

The UTSA Center for Public Opinion Research explains how polls are put together.

“The way I like to describe polling to students and other folks aren’t familiar is that essentially what you’re doing is you’re taking a sample from a larger population, and you want that sample to look like the larger population,” said Bryan Gervais, director of the research center.

He offered a simpler comparison.

“If you go to try soup, a bowl of soup you never had before at a restaurant, you don’t need to eat the entire bowl of soup to know if you like the soup or not,” Gervais said.

Part of his job at the center involves putting polls together, conducting them and analyzing the results. With election polling, he said no one is reinventing the wheel.

“Lots of times, you’re using questions that have already been written before, that are sort of standard within the industry. They’ve been tested, they’ve been validated,” Gervais said.

Election polling carries its own problem, he said.

“There’s always an inherent challenge, because you’re trying to get a sample that looks like a population which does not yet exist,” Gervais said. “The actual people who vote isn’t going to be real until the votes have actually been cast.”

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There is no way to know how people will actually vote, or whether they will, Gervais said. But pollsters can look at whether people have voted before, and how often.

“We’re looking at actual past voter history. We can’t see how people vote, but we can see the frequency with how people actually vote,” he said.

Gervais said checking a pollster’s credibility is not difficult. A good place to check is the American Association of Public Research.

“They have something called their transparency initiative,” Gervais said. “They’ll list people who are part of their transparency initiative, and are basically credentialed, in that they are open about their methodology, they make clear and they’re transparent about how they collect their information.”

Polling organizations have to be recertified every year, and results from known organizations that have been around for years are generally reliable, Gervais said.

Before trusting a poll, voters should ask who conducted it, who paid for it, how many people participated, when they were questioned and exactly what they were asked.

Online polls where anyone can click and vote may not represent the electorate.

Margin of error matters, too. If one candidate has 49% and another has 47%, with a margin of error of plus or minus three points, that two-point lead does not necessarily mean the candidate is ahead.

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