A embodiment is disclosed for learning user interests based on user actions and then applying the learned knowledge to rank, recommend, and/or filter items, such as e-mail spam, based on the level of interest to a user. The embodiment may be used for automated personalized information learning, recommendation, and/or filtering systems in applications such as television programming, web-based auctions, targeted advertising, and electronic mail filtering. The embodiment may be structured to generate item descriptions, learn items of interest, learn terms that effectively describe the items, cluster similar items in a compact data structure, and then use the structure to rank new offerings.