Taxonomic free sorting

Free sorting is a quick and reliable means to assess similarities among a set of stimuli by a panel of subjects. In this procedure, subjects form as many groups of stimuli as they consider necessary, with the understanding that each group is formed with stimuli that are perceived as similar. However, no information is available about the structure of the groups formed by each subject. In practice, these groups are considered as equally distant from each other. This is a questionable assumption as it may not reflect the perception of the subjects towards the stimuli. Taxonomic free sorting is designed to cope with this problem. Once the subjects have achieved the free sorting of the stimuli, they are instructed to organize, step by step, the stimuli into a hierarchical structure thus giving more insight into the similarities among products. Statistical treatments of the data thus obtained are discussed and the procedure of evaluation is illustrated on the basis of a case study. (C) 2011 Elsevier Ltd. All rights reserved.