Exploring the effect of a middle response category on response style in attitude measurement

In this research we focus on the link between response style behaviour in answering rating data such as Likert scales and the number of response categories that is offered. In a split-ballot experiment two versions of a questionnaire were randomly administered. The questionnaires only differed in the number of response categories, i.e. 5 vs. 6 categories. In both samples a latent-class confirmatory factor analysis revealed an extreme response style factor. The 6-response categories version, however, revealed the more consistent set of effects. As far as the content latent-class factors, i.e. familistic values and ethnocentrism, are concerned, results were fairly similar. However, a somewhat deviant pattern regarding the familistic values items in the 6-response categories version suggested that this set of items is less homogeneous than the set of ethnocentric items. The effect of gender, age and education was also tested and revealed similarities as well as differences between the two samples.