Interviewers,Interviewer Continuity,and Panel Survey Nonresponse

It is widely known that in practice, different interviewers have different response rates, though there has been no systematic examination of whether this is because of differences among interviewers or differences among those areas allocated to the interviewers (area effects), or both. Furthermore, the conventional wisdom in survey research suggests that it is advisable to have the same interviewers return to the same respondents in order to maintain good response rates in longitudinal surveys, though once again there has been very little documented experimental research to support this. This paper makes use of the interpenetrated sample design experiment in Wave 2 of the British Household Panel Study (BHPS) (i) to explore the effects of interviewers' background characteristics and years of experience on response rates, (ii) to identify and estimate the differential effects of interviewers on response rates and compare the magnitudes of area and interviewer effects, and (iii) to investigate the impact of interviewer continuity. The analysis is facilitated by the use of cross-classified multilevel modelling. The paper also looks at the issue of interviewer continuity qualitatively, through the impressions of the interviewers themselves.     

Cognitive interviewing as tool for enhancing the accuracy of the interpretation of quantitative findings

This paper contrasts findings from a quantitative survey with those from a cognitive interviewing follow-up investigation on a subset of the same respondents. The data were gathered as part of a larger study to explore measurement error across three modes of data collection, but this paper focuses on the question format experiments rather than the mode effects part of the larger study. Three examples are presented which demonstrate how cognitive interviewing can cast new light on quantitative results by increasing the accuracy of the inferences made. These include instances where: (1) quantitative indicators of poor respondent behaviour (e.g., acquiescence bias on agree/disagree questions) are over-estimates, (2) similar quantitative response distributions across satisfaction and behavioural questions (from a fully-labelled versus end-labelled experiment) imply similar respondent satisficing behaviour, but cognitive interviews show that different response processes are at work and (3) unlikely quantitative findings (from an experiment comparing 3 vs. 7 or 8 response options) could easily be dismissed as due to chance but were instead the result of unforeseen respondent difficulties. The paper concludes with a discussion of the value of using a cognitive interviewing follow-up study as a tool in the interpretation of ambiguous quantitative findings.     

The Importance of Experimental Control in Testing the Impact of Interviewer Continuity on Panel Survey Nonresponse

The conventional wisdom in survey research suggests that it is advisable to have the same interviewers return to the same respondents in order to maintain good response rates in longitudinal surveys. There has been, however, very little documented experimental research to support this. Work conducted by Campanelli and O'Muircheartaigh (1999) using a subsample of the British Household Panel Study (BHPS) at Wave 2 with experimental control of the allocation of respondents to interviewers showed no evidence of a positive continuity effect on nonresponse; more extensive analysis by Laurie et al. (1999) of the full BHPS sample using Waves 2 through 4 presents contradictory results. This paper extends the earlier analysis and shows that these differences in findings are due to the lack of experimental control for the inferences from the full BHPS sample in the Laurie et al. (1999) report rather than the shorter time frame considered in Campanelli and O'Muircheartaigh (1999). This paper also considers variation in interviewer continuity effects across areas through the use of multilevel statistical models.