LATENT CLASS ANALYSIS OF SURVEY QUESTIONS THAT INCLUDE DON'T KNOW RESPONSES.

This paper develops and describes latent class models which can be used to analyze dichotomous questions that include don't know (DK) responses. The models allow the researcher to account for different origins of the DK response; in particular, to account for DKs originating from nonattitudes, from equivocation, from an item whose cut point lies near a respondent's ideal point on the attitude, and from item misunderstanding. The models are illustrated on data involving the trade-off between environmental and economic concerns obtained by mail survey in the Pittsburgh, Pennsylvania, area. A model which includes a modified Guttman scale structure for substantive attitude holders and a separate DK class fits these data very well. In order to show the usefulness of the models, the respondents are assigned to latent classes according to this model and the characteristics of the latent classes are contrasted on attitudinal, behavioral, and demographic variables. [ABSTRACT FROM AUTHOR]