Patent ID: 7171620

Claim:
A method for managing retention of a document submitted to a recommender system, comprising: analyzing a document's substance to compute a lifetime of the document; defining a visibility value that estimates the document's importance to the users of the recommender system; determining over a time interval: (a) whether higher quality siblings of the document exist in the recommender system, and (b) whether a user action or an event has occurred; adjusting the visibility value of the document in the recommender system as a function of: (a) the user action when the user action occurs over the time interval, and (b) the document's substance when an event occurs over the time interval; decreasing the visibility value of the document in the recommender system as a function of the document's substance when no user action or event occurs over the time interval, the visibility value thereby decreasing continuously over the time interval within the computed lifetime; and removing the document from the recommender system when: (a) higher quality siblings of the document exist in the recommender system, or (b) the visibility value of the document in the recommender system is less than a threshold value.