The information overload on the Web has created a great need for efficient filtering mechanisms. Many sites (e.g., CNN and Quicken) address this problem by allowing a user to create personalized pages that contain only information that is of interest to the user. We propose a new approach for personalization that improves on existing services in three significant ways: the user can create personalized pages with information from any site (without being restricted to sites that offer personalization); personalized pages may contain information from multiple Web sites (e.g., a user can create a personalized page that contains not only news categories from her favorite news sources, but also information about the prices of all stocks whose names appear in the headlines of selected news, and weather information for a particular city); and users have more privacy since they are not required to sign up for the service. In order to build a personalization service that is general and easy to ...