Abstract: A computer-implemented method is provided, which includes constructing, by a computer system, first and second user profiles for respective first and second users, by observing respective online behaviors of the first and second users, respectively. The computer system identifies that the first and second users have similar interests. Responsively to the identifying, the computer system transfers information to the first user profile from the second user profile, thereby modifying the first user profile. Content is presented to the first user responsively to the modified first user profile.

Abstract: A computer-implemented method includes receiving from a user, by a search system, a search query comprising terms. Using at least one association graph comprising terms, the search system generates a suggested replacement query by designating one or more of the terms of the search query as anchor terms, and the remaining terms of the search query as non-anchor terms, and replacing one or more of the non-anchor terms of the search query with one or more suggested replacement terms, to generate the suggested replacement query that includes the one or more anchor terms and the one or more suggested replacement terms. The suggested replacement query is presented to the user. Responsively to a selection of the suggested replacement query by the user, the search query received from the user is replaced with the suggested replacement query, and search results are generated responsively to the suggested replacement query and presented.

Abstract: A computer-implemented method is provided, including receiving a search query from a user during a search session, and presenting information to the user responsively to the search query. After an indication that the user takes an action related to the search session is received, a portion of the presented information is identified that the user did not select prior to taking the action, and respective scores are assigned to search results generated responsively to the search query, including lowering one or more of the scores of the respective search results that are characterized by the non-selected portion of the presented information. The search results are ranked according to the scores, and presented to the user. Other embodiments are also described.