Patent attributes
A television program recommender is disclosed that automatically identifies changes in viewing preferences. Once changing viewing preferences are identified, the disclosed television programming recommender can (i) adapt the generated television program recommendations to such changes in viewing preferences, or (ii) more efficiently manage the storage of the viewing history. For cyclical or periodic changes in viewing preferences, the television programming recommender generates television program recommendations using a sub-set of the viewing history from a corresponding earlier time period. Likewise, for true or permanent changes in viewing preferences, the television programming recommender optionally generates television program recommendations using the most recent sub-set of the viewing history, which most likely reflects the current viewing preferences. In a further variation, program recommendations can be generated using a combination, such as the union or intersection, of recommendations based on viewing histories from two different periods of time. The television programming recommender can confirm that viewing preferences have not changed significantly over time, and thereafter delete portions of the viewing history without loss of any performance in the generated recommendations.