Collaborative-filtering contextual model based on explicit and implicit ratings for recommending items
View Patent ↗Methods and apparatus for a recommendation system based on collaborative filtering is provided. Explicit and implicit ratings of items by network users are used to create a contextual model. The explicit ratings comprise different rating types regarding different item attributes. The implicit ratings comprise different rating types derived from different user events and may include recency, intensity, or frequency ratings. The contextual model may be optimized for a specific objective function, such as click-through-rate or conversion rate. In other embodiments, item information is used to produce a content model where item information for an item is encoded as metadata into a document that represents the item. The contextual or content model is used to recommend one or more items to a current user. The basic unit of the recommendation system may be an item set of two or more items or a particular sequence of two or more items.
1. A method for implementing a collaborative-filtering based recommendation system for recommending one or more items among a plurality of items to a current user of a network, an item representing a product, service, webpage, audio, or document, the method comprising:
producing a model based on explicit ratings of the plurality of items from a plurality of previous network users and implicit ratings of the plurality of items based on user events of the plurality of previous network users, wherein the implicit ratings comprise recency, intensity, and frequency ratings of user events for the plurality of items, a recency rating of a user event for an item indicating how recent the user event occurred for the item, a more recent user event for the item having a higher recency rating value than a less recent user event for the item, an intensity rating of a user event for an item reflecting a number of times the user event occurred regarding the item, and a frequency rating of a user event for an item reflecting a number of times the user event occurred regarding the item over a predetermined period of time, the model comprising a plurality of similarity measurements, each similarity measurement reflecting a level of similarity between two items in the plurality of items;
receiving a first rating of a first item from the current user; and
determining the one or more recommended items by producing a predicated rating for each item in the plurality of items, the predicated rating of an item being produced using the received first rating and a similarity measurement, retrieved from the model, that reflects a level of similarity between the item and the first item.
2. The method of claim 1 , further comprising:
serving information relating to the one or more recommended items to the current user, wherein information relating to the one or more recommended items comprises text, an image, a hyperlinik, video, or audio.
3. The method of claim 1 , wherein:
explicit ratings comprise a plurality of different explicit rating types for a plurality of different item attributes; and
implicit ratings comprise a plurality of different implicit rating types based on a plurality of different user events comprising a plurality of different user interactions with a server.
4. The method of claim 3 , wherein a user event comprises performing a search relating to an item, selecting a hyperlinik relating to an item, viewing information relating to an item, purchasing an item, printing an item, listening to an item, or downloading an item.
5. The method of claim 1 , wherein an item further comprises a set of two or more items or a specific sequence of two or more items.
6. The method of claim 1 , wherein the plurality of similarity measurements comprises a plurality of different levels of similarity.
7. The method of claim 1 , wherein the predicated rating of an item comprises the rating predicted to be given by the current user for the item.
8. The method of claim 1 , wherein determining the one or more recommended items further comprises selecting the items having the top Y predicated ratings, Y comprising a predetermined number.
9. The method of claim 1 , wherein the recency rating of a user event for an item is determined using a date and time logged for the user event for the item.
10. A system for implementing a collaborative-filtering based recommendation system for recommending one or more items among a plurality of items to a current user of a network, an item representing a product, service, webpage, audio, or document, the system comprising:
a server computer system comprising:
a scoring module configured for:
producing a model based on explicit ratings of the plurality of items from a plurality of previous network users and implicit ratings of the plurality of items based on user events of the plurality of previous network users, wherein the implicit ratings comprise recency, intensity, and frequency ratings of user events for the plurality of items, a recency rating of a user event for an item indicating how recent the user event occurred for the item, a more recent user event for the item having a higher recency rating value than a less recent user event for the item, an intensity rating of a user event for an item reflecting a number of times the user event occurred regarding the item, and a frequency rating of a user event for an item reflecting a number of times the user event occurred regarding the item over a predetermined period of time, the model comprising a plurality of similarity measurements, each similarity measurement reflecting a level of similarity between two items in the plurality of items;
receiving a first rating of a first item from the current user; and
determining the one or more recommended items by producing a predicated rating for each item in the plurality of items, the predicated rating of an item being produced using the received first rating and a similarity measurement, retrieved from the model, that reflects a level of similarity between the item and the first item.
11. The system of claim 10 , wherein:
the scoring module is further configured for serving information relating to the one or more recommended items to the current user; and
information relating to the one or more recommended items comprises text, an image, a hyperlinik, video, or audio.
12. The system of claim 10 , wherein:
explicit ratings comprise a plurality of different explicit rating types for a plurality of different item attributes; and
implicit ratings comprise a plurality of different implicit rating types based on a plurality of different user events comprising a plurality of different user interactions with a server.
13. The system of claim 12 , wherein a user event comprises performing a search relating to an item, selecting a hyperlinik relating to an item, viewing information relating to an item, purchasing an item, printing an item, listening to an item, or downloading an item.
14. The system of claim 10 , wherein an item further comprises a set of two or more items or a specific sequence of two or more items.
15. The system of claim 10 , wherein the plurality of similarity measurements comprises a plurality of different levels of similarity.
16. The system of claim 10 , wherein the predicated rating of an item comprises the rating predicted to be given by the current user for the item.
17. The system of claim 10 , wherein the scoring module is further configured for determining the one or more recommended items by selecting the items having the top Y predicated ratings, Y comprising a predetermined number.
18. The system of claim 10 , wherein the recency rating of a user event for an item is determined using a date and time logged for the user event for the item.