The amount of information available on the Web has increased rapidly, reaching levels that few would ever have imagined possible. We live in what could be called the "informationexplosion era," and this situation poses new problems for computer scientists. Users demand useful and reliable information from the Web in the shortest time possible, but the obstacles to fulfilling this demand are many including language barriers and the so-called "long tail." Even worse, users may provide only vague specifications of the information that they actually want, so that a more concrete specification must somehow be inferred by Web access tools. Natural language processing (NLP) is one of the key technologies for solving the above Web usability problems. Almost all the Web page provide with the essential information in the form of natural language texts, and the amount of these text information is huge. In order to offer solutions to these problems we must perform searching an...