Introduction

Abstract

Today we are in an era of information explosion and overload. The amount of information available in the World Wide Web is exploding, and the web’s infrastructure acts as a huge storage of electronically linked web documents. Although the web made it possible to access and share information and services anywhere in the Internet, human users are increasingly dissatisfied with being able to browse static information (e.g. news, weather, hotel information), only, and having to manually filter desired information out of thousands of documents returned by the current search engines, e.g. Google or Yahoo!. Instead, they desire the next generation of the web to be intelligent and to provide electronic services, but not static data, and to support them in automatically performing both simple and complex tasks.