Abstract:
In customizing a user profile employed by a recommendation system, users are prompted for feedback regarding content that is the subject of the recommendation system. Only feedback that does not degrade performance of the recommendation system, as measured by the error rate, is accepted and utilized to modify the user profile. Feedback that would degrade performance is discarded without being employed to alter the user profile. In this manner, error is continually driven toward a minimum by system changes based on feedback.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention is directed, in general, to use of feedback in recommendation systems and, more specifically, to selective use of user feedback to improve performance of recommendation systems. 
     BACKGROUND OF THE INVENTION 
     Systems employed in generating guides, or information regarding available options in connection with a particular activity, may produce suggestions or recommendations for the user. Examples of such systems include on-line shopping or information retrieval systems and systems for delivery of content, particularly entertainment content such as audio or video programs, games and the like. In the case of systems delivering entertainment content, automatic action may be triggered by the generation of a suggestion or recommendation, such as caching, during a period when the entertainment content is not being utilized by the user, at least a portion of available entertainment content for later presentation to the user. 
     In generating suggestions or recommendations, suitable results are most often obtained by employing, at least in part, an explicit user profile of likes and dislikes. In general, such explicit user profiles are generated by user access and completion of a profiling questionnaire, within which the user rates various meta-data descriptors such as (for video content) genre, actor(s), director, title, etc. 
     Populating or developing an explicit user profile typically must be initiated by the user, and often requires (or allows) users to independently enter values for meta-data descriptors, such as an actor&#39;s name or the title of video content. This forces the user to attempt to remember, at the time of profile creation, all relevant values for meta-data descriptors on which actions employing the profile should be based, which is difficult if not impossible. 
     On the other hand, displaying a list of all possible meta-data descriptor values to the user, from which selections may be made to populate the user&#39;s profile, will generally result in the user having to review a list of unwieldy size, or risk missing suitable descriptors. Particularly for cross-media systems (i.e., video, audio and/or other content), the user might be required to select and/or rate items from a list containing tens of thousands of entries. Either alternative (requiring the user to recall relevant items or presenting the user with a comprehensive list), or even a combination of the two approaches, is unduly demanding on the user and requires more time than a user is likely to be willing to spend on the task, and is therefore unsatisfactory. 
     A quick and effective technique for initializing a user profile involves stereotypes derived from analysis of the viewing patterns of a multitude of users. The user selects a stereotype or set of stereotypes to initialize the profile, and thereafter provides feedback to the system in order to guide the system on how to lower the “error” rate and make better suggestions. For video program recommendation systems, for example, the feedback is often in the form of a “Yes, I liked the show” or “No, I didn&#39;t like the show,” perhaps with varying degrees of intensity. 
     Not all feedback from the user, however, will improve the system&#39;s error rate. A particular piece of feedback might improve the user understanding in one area while making it worse in one or more other area(s). The Combined effect, measured in terms of error rate, could be worse, overall. 
     There is, therefore, a need in the art for improving use of feedback to adapt a stereotype to user preferences in a recommendation system. 
     SUMMARY OF THE INVENTION 
     To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide, for use in a recommendation system, customization of a user profile employed by a recommendation system in which users are prompted for feedback regarding content that is the subject of the recommendation system. Only feedback that does not degrade performance of the recommendation system, as measured by the error rate, is accepted and utilized to modify the user profile. Feedback that would degrade performance is discarded without being employed to alter the user profile. In this manner, error is continually driven toward a minimum by system changes based on feedback. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art will appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art will also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form. 
     Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words or phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, whether such a device is implemented in hardware, firmware, software or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which: 
         FIG. 1  depicts a system selectively employing feedback to customize a stereotype based user profile according to one embodiment of the present invention; 
         FIG. 2  depicts a system controller implementing selective utilization of feedback to customize a stereotype based user profile according to one embodiment of the present invention; and 
         FIG. 3  is a high level flowchart for a process of selectively employing feedback to customize a stereotype based user profile according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 through 3 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged device. 
       FIG. 1  depicts a system selectively employing feedback to customize a stereotype based user profile according to one embodiment of the present invention. Exemplary system  100  includes: a video receiver and/or playback unit  101  such as a television, a satellite, terrestrial, or cable television broadcast decoder unit, or a digital video recorder; an audio content receiver and/or playback unit  102 , such as a terrestrial or satellite radio receiver or a compact disc or digital audio player; and a Internet access device  103  such as a set-top box, personal computer or the like. In the example shown, system  100  further includes a remote control unit  104  capable of interoperating with and controlling the operation of one or more (preferably all) of video receiver  101 , audio receiver  102  and Internet access device  103 . 
     Those skilled in the art will recognize that the full construction and operation of a system employing context-based, system initiated user interactions to populate an explicit profile is not depicted or described herein. Instead, for simplicity and clarity, only so much of the construction and operation of the system as is unique to the present invention or necessary for an understanding of the present invention is depicted and described. The remainder of the construction and operation of the system may conform to conventional structures or practices known in the art. Moreover, although a video receiver, an audio receiver, an Internet access device, and a remote control are illustrated in the exemplary embodiment, those skilled in the art will recognize that the functionality described herein may be readily adapted to other types of devices such as, for example, game devices, and thereby employed with other forms of content or in connection with other activities. 
       FIG. 2  depicts a system controller implementing selective utilization of feedback to customize a stereotype based user profile according to one embodiment of the present invention. The controller hardware and programming  201  for system controller  200  may be implemented in any of video receiver  101 , audio receiver  102 , Internet access device  103 , or remote control  104  depicted in  FIG. 1  or in similar devices. Alternatively, controller hardware and programming  201  may be implemented in distributed fashion, with various portions being disposed within two or more of the devices forming the video receiver  101 , the audio receiver  102 , the Internet access device  103 , and the remote control  104 . 
     However implemented, system controller  200  includes at least one input  202  for receiving content and user input control signals, and at least one output  203  for presenting content and user interface displays. System controller  200  receives at least information regarding content available from one or more external sources (not shown) such as a broadcasting facility or a broadcast or Internet content server. In the exemplary embodiment, system controller  200  also selectively receives some of the associated content. 
     System controller  200  includes control algorithms  204  for controlling operation of one or more of the devices forming the video receiver  101 , the audio receiver  102 , the Internet access device  103 , and the remote control  104 . In the exemplary embodiment, the control algorithms  204  include a recommendation utility  205  for generating suggestions based on an explicit user profile and a profile customization (feedback) utility  206  for collecting and selectively employing user feedback to customize a user profile as described in further detail below. 
     Control algorithms  204  are operatively coupled to user interface controls  207  (e.g., buttons or keys, an infrared receiver, and/or a user interface display generator) and to a memory  208  optionally containing a content (e.g., program) guide or index  209  and one or more user profiles  210 . As shown, each user profile is, at least in part, an explicit profile in which each specific item associated with a general class or type, or meta-data categories for particular content items (e.g., genre, actor, etc.), each have an associated rating. At least initially, the ratings are derived from a stereotype selected by the user based on geographic origin, general preferences, and the like. During initialization of the system  200 , the user selects one of a plurality of stereotypes  211 , with the selected stereotype being loaded, e.g., from an external source. 
     Controller  204  employs user feedback for content to customize user profiles. By way of example, if a user is watching a video program, controller  204  may initiate a user interface query requesting the user to respond with their level of interest (rating) for the program. The feedback may be simply of limited alternatives such as “Yes, I like the program” or “No, I don&#39;t like the program.” Alternatively, the feedback may request the user to select one of a number of response gradations from “strongly like” through “don&#39;t care” to “strongly dislike.” In other embodiments, the user may be prompted for a whole number rating of the program within the range of one to ten or one to one hundred. 
     The user feedback may be input, for example, by the user selecting an arbitrary integer within a predetermined range (e.g., 1 to 100), by the user selecting from among pre-defined values (e.g., “strongly like” or “moderately dislike”), and/or by the user operating a “slider” user control within the predetermined range. 
     In the present invention, controller  204  employs user feedback selectively to customize user profiles. Specifically, before modifying a user profile based on received user feedback, controller  204  preliminarily considers the feedback and estimates the overall error using a profile including modifications according to the feedback. If the overall error is worse than before modification of the user profile based on the newly-received feedback, the system discards the feedback. In this manner, the system  200  attempts to always drive the error in one direction: down toward a minimum. 
     The error of a customized user profile may be determined in any of a variety of manners. For example, a correlation history between system recommendations and user selections and/or feedback may be maintained, and a particular user profile configuration tested against whether previous user selections (or programs which received favorable feedback from the user) would be recommended. The correlation history may be a rolling tally corresponding to a predetermined number of prior system recommendations and/or user selections/feedback, or during a particular period (e.g., the preceding six months). 
     Instead of accepting and employing all feedback from a user, the present invention intelligently utilizes only feedback that improves the recommendation performance of the system, as measured by error route. 
       FIG. 3  is a high level flowchart for a process of selectively employing feedback to customize a stereotype based user profile according to one embodiment of the present invention. The process  300  of selecting which feedback to employ and which to discard begins with user feedback being received relating to a profile derived from a stereotype (step  301 ). The user profile with any modifications appropriate for the newly received feedback is employed to determine a system error rate (step  302 ). The system error rate for the user profile without modifications according to the newly received feedback is computed (step  303 ), if necessary, and the two error rates are compared (step  304 ). If the error rate is bound to go up with the modifications to the user profile resulting from the new feedback, the new feedback is discarded without modifying the user profile (step  305 ). However, if the error rate is decreased by the modifications to the user profile based on the new feedback, the feedback is accepted and the associated modifications are incorporated into the user profile (step  306 ). Subsequent recommendations are then made based upon the modified user profile. The process then becomes idle until additional feedback is collected from the user. 
     The present invention in incorporated into a system transforming stereotypes into personalized user profiles. By selectively utilizing only user feedback that improves the recommendation performance of the system, the present invention provides for a means for continually driving the system error rate down. 
     It is important to note that while the present invention has been described in the context of a fully functional system, those skilled in the art will appreciate that at least portions of the mechanism of the present invention are capable of being distributed in the form of a machine usable medium containing instructions in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing medium utilized to actually carry out the distribution. Examples of machine usable mediums include: nonvolatile, hard-coded type mediums such as read only memories (ROMs) or erasable, electrically programmable read only memories (EEPROMs), recordable type mediums such as floppy disks, hard disk drives and compact disc read only memories (CD-ROMs) or digital versatile discs (DVDs), and transmission type mediums such as digital and analog communication links. 
     Although the present invention has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, enhancements, nuances, gradations, lesser forms, alterations, revisions, improvements and knock-offs of the invention disclosed herein may be made without departing from the spirit and scope of the invention in its broadest form.