Every poll involves a questionnaire that contains a standardized set of questions that are asked of every person. The way a question is asked can affect the answers that people give.

In an open-ended question, people answer in their own terms. In a closed-ended format, people choose from a given list of answers. (The vast majority of polling questions are closed-ended.)

One example is the “most important problem” question. This is asked most commonly in the open-ended form used by the Gallup organization: What is the most important problem facing the country today?

But some polling organizations ask the question this way: Which of the following problems is the most important one facing the country today?

This closed-ended form produces a shorter list of problems, based upon the length of the list. It may also produce other differences based upon the order in which the “problems” are listed.

Advantages and disadvantages exist in using either form. Open-ended questions are good for really getting at what is on people’s minds and having people talk about issues in their own words. On the other hand, open-ended responses can be hard to code into meaningful categories, particularly in tight time frames; they take more time to administer, so the researcher must ask fewer questions; and they can be hard to draw conclusions from if only a small number of people provide any given response.

Closed-ended questions are considerably easier to administer and analyze, but they can sometimes make people feel constrained in their answers, particularly if the categories do not include the response a person wants to provide.

Taken from Understanding and Interpreting Polls, a self-directed course at Poynter NewsU, developed in partnership with the American Association for Public Opinion Research (AAPOR).

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