19. The computing device of claim 14 , wherein the instructions, when executed by the at least one processing unit, cause the at least one processing unit to: identify an individual phrase that appears in both the individual phrase list and another individual phrase list having another individual phrase list probability distribution reflecting respective probabilities that other phrases included in the another individual phrase list correspond to the different semantic classes; and determine an individual phrase probability distribution for the individual phrase based at least on the individual phrase list probability distribution and the another individual phrase list probability distribution.
19. The computing device of claim 14 , wherein the instructions, when executed by the at least one processing unit, cause the at least one processing unit to: identify an individual phrase that appears in both the individual phrase list and another individual phrase list having another individual phrase list probability distribution reflecting respective probabilities that other phrases included in the another individual phrase list correspond to the different semantic classes; and determine an individual phrase probability distribution for the individual phrase based at least on the individual phrase list probability distribution and the another individual phrase list probability distribution. 20. The computing device of claim 19 , wherein the seed phrase also appears in the another individual phrase list.