Individualized or non-individualized IDM: What elicits consumer preferences best?

In this paper we measure consumers’ preferences for different (ethical) product attributes by questionnaires and compare the results to the ones obtained using an individualized and a nonindividualized Information Display Matrix (IDM). The latter contains only those attributes the respective respondent stated to be important for her purchase decision. The products considered in our study are ham and coffee. The findings first confirm that the IDM is able to reduce social desirability effects, a problem which likely is of relevance in surveys investigating the relevance of ethical product characteristics. Second, using sequence analysis we show that the intensity of the information search process is significantly higher in the case of an individualized IDM compared to a standardized one. In fact in the latter many consumers neglect half of the attributes presented. Thus, using a standardized IDM implies the risk that product characteristics important for consumers’ purchase decision are left out while others that are of little or no relevance are included. Third, we show that it is possible and can be considered as a methodological advancement in IDM research to apply sequence analysis to data acquired via an IDM. Different indicators allow quantifying main characteristics of consumers’ information search process and make it possible to test for significant differences between data obtained from different IDM experiments.