face-to-face contact with respondents (I suppose instant messaging could also be used, but am not aware of anyone using it yet). Self-completion questionnaires can be used for a short set of easily-understood questions; structured interviews, in which all of the questions are set in advance and the interviewer may not deviate from the list (the protocol) allow a trained researcher to ask more complex questions. Sometimes researchers use unstructured interviews allowing respondents to talk about things in the order they come into his or her head; sometimes the use a combination of structured and unstructured parts on a single questionnaire.
The particular questions used on a structured or an unstructured questionnaire can be open-ended or closed-ended. Open-ended questions allow respondents to reply in their own words. Closed-ended (sometimes called close-ended) questions ask the respondent to choose among a preset array of responses. A question asking you whether you strongly agree, agree, disagree, strongly disagree, or have no opinion is a closed-ended question. A question asking you to describe President Bush's job performance with the first word or phrase that comes to your mind is open-ended. Open-ended responses are harder to code because they are not returned to the researcher in a standard format but they can pick up additional information. Some questionnaires use both types of question. Company “exit interviews” with employees leaving for another job often includes questions like “if there was one thing you could change in the job, what would it be?” as well as questions like rate the safety of the company’s various workspaces on a one (best) to five (worst) scale.
The order of questions on a self-completed form or in an interview can make a difference because earlier questions “prime” a respondent’s mind by suggesting a particular context or putting the respondent in a particular state of mind. This priming can have any of several effects. One of the better known is the consistency effect, which stems from the fact most people want their answers to be consistent with each other. This effect operates most strongly when questions on a similar topic appear close together In 1944, while the USA was involved in World War II, D. Riggs and H. Cantrill explored the consistency effect by taking two surveys of different sets of randomly-selected respondents. One set of respondents was asked:
Should the United States allow its citizens to join the British and French armies?
The other was asked:
Should the United States allow its citizens to join the German army?
In the first version, 45% said yes to the first question and 31% said yes to the second question. When the questions were reversed, only 22% agreed with letting US citizens join the German army (“The Wording of Questions,” in H.Cantrill, editor, Gauging Public Opinion, Princeton University Press, 1944). 22% in the midst of World War II is pretty amazing, but the point of the research was that putting the allied armies first set up a pressure to be consistent and agree with allowing citizens to join an enemy army as well. Another sort of influence, the part-whole effect, occurs when one question refers to a broad topic and another to some more specific matter that can be seen as within the broad topic. H. Shuman and S. Presser tried reverse ordering of two questions with two sets of respondents in 1996. First they asked:
When they reversed the order, fewer respondents said there should be laws permitting abortion. They argued that respondents thought the more specific question asked about a special case of the broader question if the general question came first, but that the specific question was about a different topic if it came first. Thus the respondents asked about the strong likelihood of severe birth defects redefined “abortion” as not covering that situation (Questions and Answers in Attitude Surveys, Sage Publications, 1996).
Large surveys often use questions that have been used successfully in earlier surveys for either or both of two reasons. First, they