These results suggest that we can achieve the same accuracy as random labeling with around 60% of the effort by active selection of examples according to the confidence-based method described in section 3.
there is also a smaller variation in utterance length between actively and randomly selected training examples (more like 110% than the 150% for HMIHY); table 4 shows that defining effort in terms of number of phones still results in appreciable savings for active learning.