Collaborative Filtering –A technique for Web personalization which compares information gathered about a specific user’s behavior at a Web site to data about other customers with similar interests to predict what the user would like to see next. Collaborative Filtering Software –A software which makes recommendations to users based on their assumed interests. For example, Amazon and Barnesandnoble.com use collaborative filtering software to prepare personalized book recommendations: – “Customers who bought this book also bought....” – These recommendations are made just at the point of purchase, an ideal time to prompt a consumer into purchasing a related product.