Measurements of similarity have typically been obtained through the use of rating, sorting, and perceptual confusion tasks. In the present paper, a new method for measuring similarity is described, in which subjects rearrange items so that their proximity on a computer screen is proportional to their similarity. This method provides very efficient data collection. If a display hasn objects, then, after subjects have rearranged the objects (requiring slightly more thann movements),n(n-1)/2 pairwise similarities can be recorded. As long as the constraints imposed by two-dimensional space are not too different from those intrinsic to psychological similarity, the technique appears to offer an efficient, user-friendly, and intuitive process for measuring psychological similarity.
{"Subjects rearrange items so that their proximity on a computer screen is proportional to their similarity.","Subjects assign numbers between 1 and 20 to several pairs of objects, with 1 signifying very low similarity and 20 signifying very high similarity.","In one paradigm, an item is briefly flashed to the subjects, who are asked to identify it. Sometimes the item will be incorrectly identified as another item.","Subjects are presented with two items and are required to give a speeded response as to whether the items are the same or different."}