Patent ID: 8103555

Claim:
A method of recommending a product to a user of an e-commerce site selling the product through the Internet, the product being recommended in a user recommendation system, the method comprising the steps of: collecting user behavior information, wherein the user behavior information is comprised within a command signal inputted using an input device by the user in communication with the e-commerce site while the input device is accessing the e-commerce site in the user recommendation system; computing a user preference on each of a plurality of items using usefulness of the user behavior information in the user recommendation system, wherein the product is classified into a plurality of items representing the product; calculating a conditional probability value for each element included in the plurality of items in the user recommendation system; creating a recommendation tree for predicting a user preference of the user for the product, the user preference of the user for the product being predicted based on the user preference on each of the plurality of items and the conditional probability value in the user recommendation system; and recommending the product to the user based on the recommendation tree in the user recommendation system, wherein the computing of the user preference uses an ID 3 algorithm and comprises: calculating the usefulness by giving a score to the user behavior information in the user recommendation system; and computing the user preference on each of the plurality of items based on the usefulness of the user behavior information in the user recommendation system, wherein an equation for computing the user preference on each of the plurality of items is Entropy(S)=−p u≧3 log 2 p u≧3 −p u<3 log 2 p u<3 , and wherein Entropy(S) is the user preference on each of the plurality of items, p u≧3 is a probability when the usefulness of the user behavior information is greater than or equal to 3, and p u<3 is a probability when the usefulness of the user behavior information is smaller than 3.