1. A system for processing an input utterance, comprising: a processor; a speech recognition engine that causes the processor to provide a recognition result corresponding to the input utterance and a confidence score corresponding to a confidence level in the recognition result; a threshold selection component that selects, based on the input utterance, a threshold value corresponding to the input utterance; wherein, the selected threshold value is determined based on classification of the input utterance into a partition of multiple partitions in a set of training data; wherein, each of the multiple partitions is associated with a threshold value; wherein, the selected threshold value corresponding to the input utterance is the threshold value associated with the partition into which the input utterance is classified.