14. A method according to claim 13 , wherein said step of selecting a set of at least one of said additional potential input entries comprises the steps of: for each particular one of said associations, calculating a confidence score given by the degree to which said target token sequences of the particular association match the tokens in said at least one of said user input and said interpretation, scaled by the importance value of the particular association; and selecting the additional potential input entries from only those of said associations having a confidence score exceeding a predetermined minimum acceptable confidence score.
13. A method according to claim 1 , wherein said step of attempting a natural language interpretation produces an interpretation of a token in said first user input, wherein additional potential input entries in said database each associate a target token sequence with at least one potential additional token sequence, said database also including a respective importance value for each of said associations, and wherein said step of identifying additional potential input comprises the steps of: comparing to said target token sequences, tokens in at least one of said user input and said interpretation; and selecting a set of at least one of said additional potential input entries in response to said step of comparing and in dependence upon said importance values.