How Political Polling Works

Poll Questions and Answers

Questions and answers are the reason we have political polls. "Which candidate will you vote for in the election?" "Do you approve of the president's performance?" "How likely are you to vote in the midterm Congressional elections?" But the order of those questions, and the answers that respondents can choose from, can greatly affect the accuracy of the poll.

Ordering of questions is known to play a significant role in influencing responses to political polls. Let's use the example of the "horse-race" question, in which respondents are asked whom they would vote for in a head-to-head race: Candidate A or Candidate B. To ensure the most accurate result, political pollsters ask this horse-race question first. Why? Because the wording of preceding questions could influence the respondent's answer [source: Zukin].

Polls, as we mentioned, are a snapshot of the respondent's opinion in the moment the question is asked. Although many voters have a firm and long-formed opinion on politics and political candidates, other voter's views are constantly evolving -- sometimes from moment to moment. A respondent to a political poll might begin the poll with a slight lean toward Candidate A. But after a series of questions about Candidate A's views on the economy, foreign policy and social issues, the respondent might realize that he actually agrees more with Candidate B.

In pre-election polls, in particular, it is crucial to ask the race-horse question first, because voters enter the voting booth "cold," without first responding to a list of "warm-up" questions [source: Zukin].

Most political polls are conducted over the phone, and whether the pollster is a live interviewer or an automated system, there are usually set answers from which to choose. Political pollsters have discovered that the wording of these answers can offer improved insight into political opinions.

For example, the polling firm Rasmussen Reports tracks the approval rating of the president. Instead of simply asking if respondents approve or disapprove of his performance, Rasmussen asks them to choose from the following options: strongly approve, somewhat approve, somewhat disapprove or strongly disapprove. The firm has found that the "somewhat" options are important for capturing "minority" opinions [source: Rasmussen]. For example, if a registered Democrat isn't thrilled with President Obama's performance, she still might choose "approve" over "disapprove" if those were the only options. But the "somewhat disapprove" option allows her to be more honest without undercutting her support of the president. Similarly, a registered Republican could "somewhat approve" of a Democratic president without feeling he has betrayed his party.

On the next page, we'll talk about the trickiest part of creating an accurate political poll: weighting the results.