The Possibility of Mixed-Mode Surveys in Sociological Studies

Abstract:  This paper explores the possibility of the mixed-mode survey in Japan in order to ensure a wider range of respondents, focusing on the specific type of mixture that is designed to make contact with a respondent by more than one mode and in which a respondent can choose an alternative mode convenient for him or her. The dataset mainly used comes from the survey Study on the Social Composition of the Urban Local Community conducted in Shinagawa Ward of Tokyo in 1999. Three other studies are introduced for additional information. As an indicator of the effectiveness of a mixed-mode design, the response rates of four studies are examined and some improvement in the response rates is observed, compared to that of a single-mode design. Another indicator is the representativeness of a sample and it is evaluated using the data of the Shinagawa survey. When the discrepancy between valid respondents and the population on some demographic characteristics is regarded as representation bias, a mixed-mode design is found to reduce the bias. An inherent problem in a mixed-mode design is "mode effect." In order to control for the mode effect in analyses, the inclusion of an additional variable indicating "mode" in the model is recommended. It is further suggested that the interaction effects between the "mode" and the respondents' traits should be checked, on the assumption that the survey mode affects respondents differently. The attempts are made and discussed in this paper using two variables drawn from the Shinagawa survey.