1. A computer-implemented method of semantic classification, the computer-implemented method comprising: receiving, at a computerized training manager, a first utterance for use in training a first computerized semantic classifier, the first computerized semantic classifier having a set of manually-created semantic classes for labeling transcribed utterances, the first utterance being a transcribed utterance manually classified in a first semantic class within the set of manually-created semantic classes; semantically labeling the first utterance by a second computerized semantic classifier, the second computerized semantic classifier being a previously-trained computerized semantic classifier; semantically labeling existing utterances by the second computerized semantic classifier, the existing utterances accessed from a database of existing utterances, the database of existing utterances containing transcribed utterances used to train previously-trained computerized semantic classifiers; identifying, by the computerized training manager, existing utterances that are semantically similar to the first utterance based on semantic labeling from the second computerized semantic classifier; and training, by the computerized training manager, the first computerized semantic classifier using the semantically similar existing utterances.