5. The computer-implemented method of claim 1 , comprising: receiving information relating to a user's interaction with the particular resource; and updating the information about the user based on the information.
1. A computer-implemented method comprising: receiving, by a search engine and from a classifier, topic information indicating that, based at least on information about a user that was provided by the search engine to the classifier, the user is likely interested in a set of one or more topics; receiving, by the search engine, a search query with one or more terms that correspond to a subset of the topics in which the user is likely interested; identifying, by the search engine, the subset of the topics in which the user is likely interested that correspond to one or more terms in the search query; generating, by the search engine, a search results page that includes a link (i) to a particular resource that the search engine identifies as responsive to the search query, and (ii) that is encoded with topic information for the subset of topics that were indicated to the search engine by the classifier as topics in which the user is likely interested and identified by the search engine as topics that correspond to one or more terms in the search query; and providing the search results page for display.