The behavior of respondents in interview situations has been dealt on the one hand with respect to many empirical studies and on the other hand in connection with different theoretical approaches (Hyman 1954; Cannell & Kahn 1968). In this paper the most relevant theoretical explanations are discussed and systematized from the point of view of the theory of reasoned action (Ajzen & Fishbein 1980). Whereas this theory program has been used in many substantive fields, it has rarely been applied to the problem of interviewer effects and response sets. In this approach one assumes that the actors in interview situations decide according to cost-benefit calculations. The theory of reasoned action is viewed as an operationalized theory, discussed in more detail and formalized via structural equation models.

These models are empirically tested with the data of a survey specifically designed to perform such a method study. The reported contact rates of German with foreigners is the dependent variable under study. First, a model without interviewer variables is tested to explain respondent behavior in terms of norms, attitudes and some other determinants. Then the status and the age of interviewers are introduced as situational determinants of the respondents' behavior. For subgroup analyses the respondents are divided into three groups varying in the amount of the need for social approval. The models are tested according to two subgroups (low and high need for social approval) with the technique of multiple group comparison in LISREL (Jöreskog/Sörbom 1988). All models and results are interpreted in terms of the theory of reasoned action. At the end some conclusions for modelling interviewer effects and respondent behavior are discussed.