27. The non-transitory computer-readable storage medium of claim 20 , wherein associations in the query association database contain data indicating a number of usefulness indications that has been received for an association in the query association database; wherein the step of storing the association further comprises incrementing data indicating the number of usefulness indications that has been received for the association; further comprising instructions for: receiving input indicating whether the first modified query is useful; in response to the input indicating that the first modified query is useful, incrementing the data indicating the number of usefulness indications that has been received for the association for the user-submitted query.
27. The non-transitory computer-readable storage medium of claim 20 , wherein associations in the query association database contain data indicating a number of usefulness indications that has been received for an association in the query association database; wherein the step of storing the association further comprises incrementing data indicating the number of usefulness indications that has been received for the association; further comprising instructions for: receiving input indicating whether the first modified query is useful; in response to the input indicating that the first modified query is useful, incrementing the data indicating the number of usefulness indications that has been received for the association for the user-submitted query. 28. The non-transitory computer-readable storage medium of claim 27 , wherein the relevance of an association for a query in the query association database depends on how frequently usefulness indications for the association have occurred.