The Internet revolution has made an enormous quantity of information available 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 user, while searching for the information of interest, to dip into multiple sources, in a labyrinth of billion of links, often resulting in both user's disorientation and cognitive overhead. This is very different from traditional database querying, where the available information is much limited, but the user has just the duty of specifying which are the data s/he wants to retrieve in order to obtain them. Web-at-a-Glance (WAG) is a system aiming at solving the above problems by allowing the user to query (instead of browsing) the Web. WAG performs this ambitious task by constructing a personalized database, pertinent to the user's interests. The system semi-automatically gleans the most relevant information from a Web site or several Web sites, stores it into a...

The need of friendly environments for effective information access is further enforced by the growth of the global Internet, which is causing a dramatic change in both the kind of people who access the information and the types of information itself (ranging from unstructured multimedia data to traditional record-oriented data). To cope with these new demands, the interaction techniques traditionally offered to the users have to evolve and eventually integrate in a powerful interface to the global information infrastructure. The new interaction mechanisms must be especially friendly and easy-to-use, since, given the enormous quantity of information sources available on the Internet, most of the users remain "permanent novices" with respect to each one of the sources they have access to. This tutorial offers a survey of the main approaches adopted for letting the users effectively interact with the Web. Thus, it covers topics related with both extracting the information of interest spre...