With the GOP midterm convention about to get underway, kicking off the final stretch before Election Day, we are preparing for an onslaught of polling — and while it’s easier than ever to conduct a survey, it’s as difficult as ever to get it right.
At CNN, we ask pollsters to answer more than a dozen questions about their work before we cover it, from revealing who paid for the poll to sharing the technical details of their sampling and weighting.
Even if you’re not an expert on methodology, there are a few things you can look for to get a sense of whether a poll is worth your time — and to get the most information out of its results.
Here’s are some key things to look out for:
Transparency about the poll: Look for pollsters who are transparent about what they’re doing. If there aren’t many details available about who conducted and sponsored the poll, how they carried it out or what questions they asked, that’s your first sign to be skeptical.
Consider the survey’s sample: Fundamentally, polls work by talking to relatively small groups of people who are selected to be demographically representative of a much larger universe (say, “adults in the US,” or “people who are likely to vote in the next election”). Pay attention to how pollsters selected individuals to take the survey. Feel free to ignore “polls” that let anyone answer, which can’t reflect the opinions of anybody beyond those who happened to answer. When looking at the sample size of a poll, keep in mind that a relatively small but representative sample is better than a very large, unrepresentative one.
What questions did the poll ask? The way a poll question is framed can have major impacts on the results of the poll, particularly around unfamiliar candidates or complicated topics — so can the order that questions were asked in. Look for polls that share the exact wording of their questions, so that you can evaluate whether those questions seem balanced and get the clearest sense possible of what the people taking the survey actually meant by their answers.