Assessments of similarity seem to be important for a variety of cognitive acts, ranging from problem solving to categorization to memory retrieval. Similarity is important properties to both human cognitive activities and computer. Therefore interdisciplinary research has already accumulated a number of facts and different theories were put forward. According to the proposed theory of representation of similarity, a shape is presented internally by the response of a small number of tuned modules, each broadly selective for some reference shape, whose similarity to the stimulus it measures. This shape space supports representations of distal shape similarity that are verdical as second-order isomorphisms (i.e. correspondence between distal and proximal similarities among shapes, rather than between distal shape and their proximal representations). An ensemble or a Chorus of n classifiers maps the distal shape to a proximal representation space R k. In the domain of shape perception, Multidimensional Scaling (MDS) has been applied in the analysis of perceived similarity among relatively simple two-dimensional figures. The column organization of the inferotemporal cortex (IT) seems to be equally compatible with the notion that entire objects are represented, as called by the Chorus model. Assessments of similarity seem to be important for a variety of cognitive acts, ranging from problem solving to categorization to memory retrieval. Therefore interdisciplinary research has has a number of facts and different studies were put forward. According to the proposed theory of representation of similarity, a shape is submitted internally by the response of a small number of tuned modules, each broadly selective for some reference shape, whose similarity to the stimulus it measures. This shape space supports representations of distal shape similarity that are verdical as second-order isomorphisms (ie correspondence between distal and fewer similarities among shapes, rather than between distal shape and their proximal representations). An ensemble or a Chorus of n classifiers maps the distal shape to a proximal representation space R k. In the domain of shape perception, Multidimensional Scaling (has been applied in the analysis of perceived similarity among relatively simple two-dimensional figures. The column organization of the inferotemporal cortex (IT) seems to be equally compatible with the notion that the entire objects are represented, as called by the Chorus model.