Finding the most descriptive substructures in graphs with discrete and numeric labels

Abstract

Many graph datasets are labelled with discrete and numeric attributes. Frequent substructure discovery algorithms usually ignore numeric attributes; in this paper we show that they can be used to improve discrimination and search performance. Our thesis is that the most descriptive substructures are those which are normative both in terms of their structure and in terms of their numeric values. We explore the relationship between graph structure and the distribution of attribute values and propose an outlier-detection step, which is used as a constraint during substructure discovery. By pruning anomalous vertices and edges, more weight is given to the most descriptive substructures. Our experiments on a real-world access control database returns similar substructures to unconstrained search with 30% fewer graph isomorphism tests. © 2013 Springer-Verlag.