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.     

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.