Deep Architectures for Learning Context-dependent Ranking Functions
This addresses a limitation in ranking algorithms for applications like recommendation systems, though it is incremental in extending existing methods to handle context-dependence.
The paper tackles the problem of context-dependent ranking in preference learning, where object utility depends on available alternatives, and presents two neural network approaches that are evaluated on benchmark tasks, showing competitive performance.
Object ranking is an important problem in the realm of preference learning. On the basis of training data in the form of a set of rankings of objects, which are typically represented as feature vectors, the goal is to learn a ranking function that predicts a linear order of any new set of objects. Current approaches commonly focus on ranking by scoring, i.e., on learning an underlying latent utility function that seeks to capture the inherent utility of each object. These approaches, however, are not able to take possible effects of context-dependence into account, where context-dependence means that the utility or usefulness of an object may also depend on what other objects are available as alternatives. In this paper, we formalize the problem of context-dependent ranking and present two general approaches based on two natural representations of context-dependent ranking functions. Both approaches are instantiated by means of appropriate neural network architectures, which are evaluated on suitable benchmark task.