1. A method comprising: determining a set of items, each of said items having at least one relationship with another one of said set of items; determining a root item from said set of items; constructing a relationship tree from said root item; populating at least a portion of an initial distance matrix based on said relationship tree; populating a dissimilarity matrix based on a plurality of said relationship; combining said dissimilarity matrix, a weighting value, and said initial distance matrix to determine a second distance matrix.