Cognitive Interviewing

Cognitive interviewing is a psychologically oriented method for empirically studying the ways in which individuals mentally process and respond to survey questionnaires. Cognitive interviews can be conducted for the general purpose of enhancing the understanding of how respondents carry out the task of answering survey questions. However, the technique is more commonly conducted in an applied sense, for the purpose of pretesting questions and determining how they should be modified, prior to survey fielding, to make them more understandable or otherwise easier to answer.

The notion that survey questions require thought on the part of respondents is not new and has long been a central premise of questionnaire design. However, cognitive interviewing formalizes this process, as it approaches the survey response task from the vantage point of cognition and survey methodology (CASM), an interdisciplinary association of cognitive psychologists and survey methodologists. The cognitive interview is generally designed to elucidate four key cognitive processes or stages: (1) comprehension of the survey question; (2) retrieval from memory of information necessary to answer the question; (3) decision or estimation processes, especially relating to the adequacy of the answer or the potential threat it may pose due to sensitive content or demands of social desirability; and (4) the response process, in which the respondent produces an answer that satisfies the task requirements (e.g. matching an internally generated response to one of a number of qualitative response categories on the questionnaire).

For example, answering the survey question In the past week, on how many days did you do any work for pay? requires that the respondent comprehends the key elements “week” and “work for pay,” as well as the overall intent of the item. He or she must retrieve relevant memories concerning working and then make a judgment concerning that response (for instance, the individual may have been home sick all week, but in keeping with the desire to express the notion that he or she is normally employed, reports usual work status). Finally, in producing a response, the respondent will provide an answer that may or may not satisfy the requirements of the data collector (e.g. “Four”; “Every day”; “Yes, I worked last week”). The cognitive model proposes that survey questions may exhibit features that preclude successful cognitive processing and that may result in survey response error (in effect, answers that are incorrect). In the preceding example, the question may contain vague elements (“week”; “work for pay”) that create divergent interpretations across respondents; or it may induce biased responding (e.g. the socially desirable impulse to provide a nonzero response).