We describe a system for the refinement of spoken search queries. Given an initial query ("Northern Italian restaurants in New York"), instead of requiring a fully-specified followup query ("Korean restaurants in New York"), a more natural, abbreviated update query ("Korean instead") may be spoken. The system consists of a parsing step to identify the type and arguments of the refinement, a candidate generation step to enumerate the possible refinements, and a model classification step to select the best refinement. We present results on test query refinements given both to this system and to human judges that show the automated system outperforms the human judges on that data set.

Index Terms: spoken dialog systems, voice search, query refinement