1. A method operative in a data processing system, the method comprising the steps of: performing the following steps for each one of a plurality of participants: displaying a plurality of item cards, accepting input regarding logical groupings into which said item cards are sorted, saving a record of said logical groupings and a record of ones of said item cards that were not sorted into one of said logical groupings; calculating, for all of said participants by means of cluster analysis, an indication of perceived distance between ones of said item cards, wherein said calculating step adjusts calculations to take into account instances where ones of said item cards are not sorted.