1. A computer-implemented method comprising: ranking, using one or more computers, indexed queries based on a respective query rank of each indexed query, the query rank calculated based on a frequency of occurrence of the indexed query and a user satisfaction score of the indexed query, the indexed queries including highly-ranked queries and nearby queries that are queries that have a statistically significant probability of being revised to one of the highly-ranked queries, wherein the user satisfaction score of a particular indexed query is determined from estimates of lengths of clicks on search results, wherein the estimates of the lengths of clicks on search results are based on a duration of time from a selection of a search result for the particular indexed query to a subsequent selection of another search result; calculating a respective revision score for each indexed query as a function of a revision probability of a first query and the respective query rank for the particular indexed query, the revision probability based on at least one of a semantic similarity or syntactic similarity between the first query and the particular indexed query; selecting one of the indexed queries as an alternative query to the first query based on the respective revision score of the selected query; and providing the selected query as a suggested revision for the first query.
1. A computer-implemented method comprising: ranking, using one or more computers, indexed queries based on a respective query rank of each indexed query, the query rank calculated based on a frequency of occurrence of the indexed query and a user satisfaction score of the indexed query, the indexed queries including highly-ranked queries and nearby queries that are queries that have a statistically significant probability of being revised to one of the highly-ranked queries, wherein the user satisfaction score of a particular indexed query is determined from estimates of lengths of clicks on search results, wherein the estimates of the lengths of clicks on search results are based on a duration of time from a selection of a search result for the particular indexed query to a subsequent selection of another search result; calculating a respective revision score for each indexed query as a function of a revision probability of a first query and the respective query rank for the particular indexed query, the revision probability based on at least one of a semantic similarity or syntactic similarity between the first query and the particular indexed query; selecting one of the indexed queries as an alternative query to the first query based on the respective revision score of the selected query; and providing the selected query as a suggested revision for the first query. 9. The method of claim 1 , in which the suggested revision is displayed to a user in a location dependent upon a relative strength of a confidence measure associated with the alternative revision.