20. The non-transitory computer readable storage medium of claim 19 , wherein selecting the candidate phrases to include in the list comprises selecting candidate phrases having similarity scores above a threshold.
19. The non-transitory computer readable storage medium of claim 11 , wherein creating the list of candidate phrases comprises: calculating the similarity scores between candidate phrases in the list and the infixes of the queries in the second group; sorting the candidate phrases using the similarity scores to create a ranking; and selecting candidate phrases to include in the list based at least in part on the ranking.