A paired comparison approach for the analysis of sets of Likert-scale responses

This paper provides an alternative methodology for the analysis of a set of Likert
responses measured on a common attitudinal scale when the primary focus of interest is on
the relative importance of items in the set. The method makes fewer assumptions about the
distribution of the responses than the more usual approaches such as comparisons of means,
MANOVA or ordinal data methods. The approach transforms the Likert responses into paired
comparison responses between the items. The complete multivariate pattern of responses
thus produced can be analysed by an appropriately reformulated paired comparison model.
The dependency structure between item responses can also be modelled flexibly. The advantage
of this approach is that sets of Likert responses can be analysed simultaneously within
the Generalized Linear Model framework, providing standard likelihood based inference for
model selection. This method is applied to a recent international survey on the importance of
environmental problems.