19. The medium of claim 17 , wherein the operations further comprise: determining an ambiguity value for each of the one or more displayed possible intended actions for each of the two or more displayed candidate transcriptions and for each of the two or more displayed possible intended actions for the particular transcription; determining that the ambiguity value for the particular displayed possible intended action satisfies a threshold; automatically invoking the particular displayed possible intended action based on determining that the ambiguity value satisfies the threshold; determining that the user has cancelled the particular displayed possible intended action; and decrementing the ambiguity value for the particular displayed possible intended action based on determining that the user has cancelled the particular displayed possible intended action.
17. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising: obtaining information specifying two or more displayed candidate transcriptions of a single voice command and one or more displayed possible intended actions for each of the two or more displayed candidate transcriptions of the single voice command, including two or more displayed possible intended actions for a particular transcription of the two or more displayed candidate transcriptions of the single voice command; receiving data indicating a selection of a particular displayed possible intended action from among the one or more possible displayed intended actions for each of the two or more transcriptions of the single voice command and the two or more possible displayed intended actions for the particular transcription; providing data indicating the selection of the particular displayed possible intended action to a server; and invoking the selected particular displayed possible intended action.