11. The computer-readable medium of claim 9 , wherein the operations further comprise: determining a match count for the query term substitution rule, wherein the match count for the query term substitution rule indicates a quantity of revised search queries that (i) were generated using the query term substitution rule to include the query term and the substitute term, and (ii) were each used in identifying a respective set of search results, one or more of which were associated with text that included the substitute term.
13. The computer-readable medium of claim 11 , wherein the operations further comprise: determining that a no-match ratio between the no-match score and the query count does not satisfy a no-match ratio threshold; determining that a click ratio between the click score and the match count does satisfy a click ratio threshold; and in response to determining that (i) the no-match ratio does not satisfy the no-match ratio threshold and (ii) the click ratio does satisfy the click ratio threshold, retaining the query term substitution rule.