An
information retrieval system allows a user to search a
database of informational items for a desired informational item, and presents the search result in the form of matching index entries in the order of relevance. The
information retrieval system in accordance with the principles of the present invention assigns a relevance rating to each of the index entries without requiring an explicit input from the user with respect to the usefulness or the relevance of the retrieved information corresponding to the respective index entries. When the user selects and retrieves an informational item through a
list of index entries presented by the retrieval
system, as a result of a search, the relevance rating of the selected informational item is increased by a predetermined amount. The relevance rating of the selected informational item is further adjusted based on any actions the user takes subsequent to the initial selection of the informational item if the subsequent act indicates that the relevance of the selected informational item may be less than what is reflected by the rating increase by the predetermined amount. Ratings of the informational items in the
database are determined from implicit suggestions from the usage of the retrieval system and the
database by the user rather than from an explicit
user input. In another aspect of the present invention, the ratings are allowed to decay over time to minimize the tendencies for historical usage biased rating, and to provide more temporally accurate ratings. The most recently accessed time of each of the informational items in the database is compared to a predetermined stale
access time threshold, and if the most recently accessed time is older than the threshold, than the rating of the corresponding informational item is decreased to reflect the dated nature of the information contained within the item.