1. A computer-implemented method, comprising: identifying, within a search log of private search queries and corresponding post-search activity, a plurality of non-private n-grams contained in the private search queries that satisfy a privacy criterion; generating, from the search log, based on the plurality of non-private n-grams, a plurality of query patterns; determining, from the search log, aggregate search activity statistics associated with each of the plurality of query patterns, wherein aggregate search activity statistics associated with each query pattern are indicative of search activity associated with a plurality of private search queries in the search log that match the query pattern; and in response to a determination that aggregate search activity statistics for a given query pattern satisfy a performance criterion, altering a methodology for generating data that is presented in response to search queries that match the given query pattern based on aggregate search activity statistics associated with the given query pattern.