Methodologies for Evaluating Survey Questions: Some Lessons from the Redesign of the Current Population Survey
Various techniques have been developed over the years to pretest new survey questions or to evaluate the effectiveness of preexisting questions. As part of the current effort to redesign the Current Population Survey (CPS), researchers from the Census Bureau and the Bureau of Labor Statistics used a variety of methods to evaluate questions designed to elicit accurate labor force data and to assess the quality of interviewer-respondent interactions. The initial two phases of the redesign utilized Computer-Assisted Telephone Interviewing (CATI) and a Random Digit Dialing (RDD) sampling plan, and hence is referred to as the CATI/RDD Test. During the first phase of the CATI/RDD Test, the current version of the CPS questionnaire ("A") was compared with two alternative versions ("B" and "C") which were developed on the basis of earlier laboratory and field research. The principal product of this first phase was a single alternative questionnaire ("D"), which comprised the best questions from versions B and C, and a number of other questions deemed necessary given the results of phase one analyses. In the second phase of the field test, versions A and D were compared. The main purpose of phase two was to fine tune version D, which with minor revisions will become the revised CPS questionnaire for the 1990s.
Four general pretesting methods were used in the evaluation of alternative CPS questionnaires during phases one and two. These methods are listed and briefly described below:
- Systematically Coded Interviewer-Respondent Interactions. Six monitors coded interactions between interviewers and respondents while interviews were in progress. Both interviewer behaviors (e.g., exact reading of question, minor/major change in wording, probes) and respondent behaviors (e.g., adequate answer, inadequate answer, request for clarification) were coded.
- Interviewer Debriefing. During phase one, interviewers were asked to report in a self-administered questionnaire, and later to discuss in a focus group format, their impressions on various aspects of the alternate questionnaires (e.g., version preferences, problematic questions/series, difficulties with asking certain questions). During phase two, only focus groups were conducted.
- Field-based Respondent Debriefing. After completing their monthly CPS CATI/RDD interview, most respondents were asked two or three sets of debriefing questions that were keyed to responses given during the main labor force interview. Among other purposes, these debriefing questions were designed to establish if key labor force concepts were being misunderstood and to evaluate whether or not questions in the main survey were superfluous. Ten percent of the respondents were read short vignettes and asked how they would classify the main character in each scenario (i.e., as working or looking for work).
- Item-based Response Analysis. These analyses involved statistical comparisons of response distributions and nonresponse rates among comparable question sets for alternative versions of the CPS questionnaire. The focus of the paper is on what we have learned about the strengths and weaknesses of each of these methods in terms of implementation, interpretation, and effectiveness at identifying problematic questions. The discussion is illustrated with selected results from the CATI/RDD field test.