Discriminative techniques in call routing

Call-routing is a technology that attempts to route automatically a telephone query from a customer to one of a number of destinations. In vector-based call-routing, a query is represented in a high-dimensional vector space whose axes correspond to words, or sequences of words, that appear in the vocabulary used by callers. In this paper, we examine three different discriminative techniques applied to call-routing. Although some of these techniques give very substantial reductions in error-rate on the training-set, performance on the test-set is disappointing, the most likely reason being a lack of generalisation. Using examples of mis-classified calls, we speculate on why this might occur and propose an improved approach.