Abstract: The invention uses pair-wise relations such as dissimilarity, similarity or correlation to identify related items by translating the relations into a set of points in a geometric space, where each point in the set of points represents an item, and where the distance between any two points directly corresponds to the dissimilarity value of the two items represented by the two points. A family of graphs is computed from the Voronoï diagram for the set of points. This family of graphs may be used for a variety of applications, including recommendation systems. For some applications, clustering may be used to assist in visualizing and identifying relations among items. In the case of recommendation systems, graphs reflecting customer preferences are clustered to identify customers with similar tastes.