SORT-CC: A procedure for the statistical treatment of free sorting data

A statistical approach for the analysis of free sorting data is discussed. In a first stage, the sorting data from each subject are arranged into a dataset consisting of indicator variables which reflect the memberships of the stimuli to the groups formed by the subject under consideration. Thereafter, an appropriate standardization is applied on these data and a three way statistical method, namely Common Components and Specific Weights Analysis, is performed on the datasets thus obtained. This makes it possible to take account of the individual differences among the subjects and to depict graphical displays showing the relationships among the stimuli on the one hand and among subjects on the other hand. The general strategy of analysis is illustrated on the basis of a dataset and the outcomes are compared to those of other strategies of analysis of sorting data.