CONTROLLING THE GROWTH OF A FEATURE FREQUENCY PROFILE BY DELETING SELECTED FREQUENCY COUNTS OF FEATURES OF EVENTS.

A method and system for controlling the growth of a features frequency profile of a time-ordered sequence of events, wherein each event has features specific to each event. The events are sequentially processed in an order of processing. The processing includes selecting for each event processed at least one feature comprised by the event. The processing updates a frequency count of each feature selected. The frequency counts are periodically reduced in magnitude by a reduction factor. Frequency counts are selected for deletion upon satisfaction of a condition that favors deletion of those frequency counts having a magnitude less than a threshold value. The selected frequency counts are then deleted. The present invention employs an economical use of memory to store data associated with the features frequency profile and uses a features preference profile that is more responsive to recent information than to older information.