Learning to rank typed graph walks: Local and global approaches

We consider the setting of lazy random graph walks over directed graphs, where entities are represented as nodes and typed edges represent the relations between them. This framework has been used in a variety of problems to derive an extended measure of entity similarity. In this paper we contrast two different approaches for applying supervised learning in this framework to improve graph walk performance: a gradient descent algorithm that tunes the transition probabilities of the graph, and a reranking approach that uses features describing global properties of the traversed paths. An empirical evaluation on a set of tasks from the domain of personal information management and multiple corpora show that reranking performance is usually superior to the local gradient descent algorithm, and that the methods often yield best results when combined.