Conceptual views over the Web

The Internet has made available an enormous quantity of information to a disparate variety of people. The amount of information, the typical access modality (i.e. browsing), and the open growth of the Net, force the puzzled user to search the information of interest in a labyrinth of billions of links. This is very di erent from traditional database querying, where the user has just the duty of specifying which are the data s/he wants to retrieve. We argue that, in order to provide the user with apowerful and friendly query mechanism for accessing information on the Web, the critical problem is to nd e ective ways to build models of the information of interest. In this paper we motivate the above observation by presenting notable attempts to construct systems which model the information in the Web following di erent approaches. We rst classify such systems in two categories, as being based on Database or Knowledge Representation techniques, and discuss their main advantages and disadvantages. Then, we brie y introduce an integrated approach, in which Knowledge Representation mechanisms and reasoning capabilities are coupled with traditional Database features, such as ef-The copyright of this paper belongs to the papers authors. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage