Visual query systems (VQSs) are query systems for databases that use visual representations to depict the domain of interest and express related requests. VQSs can be seen as an evolution of query languages adopted into database management systems; they are designed to improve the effectiveness of the human-computer communication. Thus, their most important features are those that determine the nature of the human-computer dialogue. In order to survey and compare existing VQSs used for querying traditional databases, we first introduce a classification based on such features, namely the adopted visual representations and the interaction strategies. We then identify several user types and match the VQS classes against them, in order to understand which kind of system may be suitable for each kind of user. We also report usability experiments which support our claims. Finally, some of the most important open problems in the VQS area are described. 1.

In recent years, there has been considerable interest in techniques that enhance the cooperative behavior of database systems and many different techniques have been developed. These techniques approach the goal of cooperation in diverse ways; the differences may be in the specific task in which they offer cooperation, in the details of the solution, and even in the very interpretation of cooperative behavior. In this article we classify many different techniques into categories of cooperation, and we survey the techniques in some of these categories. Finally, we consider the challenges that remain and offer directions for new research. O 1996 John Wiley & Sons, Inc. I.

The growth of the global Internet is causing a dramatic change in both the kind of people who access the information and the types of information itself, which range from unstructured multimedia data to traditional record-oriented data. To cope with these new needs, the interaction techniques traditionally offered to DBMS users have to evolve and eventually integrate in a powerful interface to the global information infrastructure. In particular, from the user's point of view there is the need of both effective visualizations of multimedia information and retrieval tools able to overcome the existing dichotomy between browsing and querying. This paper concentrates on the mutual relationship between database querying and Internet navigation, by reviewing some important contributions from different areas, such as information retrieval, database research, and visualization techniques. Keywords: Internet, database, user interaction, visualization 1. Introduction At the beginning, informa...

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In the design of future enviromental systems, the semantics of the data as well as the kind of queries to those systems have to be considered. Enviromental data is frequently uncertain and incomplete. Heterogeneous data structures as well as multimedia data have to be managed by the system. For interactive queries, the system should allow vague queries and query formulations that are independent of the specific structure of the data and its representation. For vague queries and imprecise data, methods developed in information retrieval can be applied. Heterogeneous data structures can be handled with concepts from object-oriented database management systems. In multimedia information systems, the problem of full integration of the different media is yet unsolved, especially in case the information a user searches for is stored in different media. We claim that the retrieval interface offerd by current database management systems is not sufficient for interactive use. In addition, funct...

In this report we introduce a general browsing model that describes intuitive ideas about browsing. In this model it is assumed that the database scheme, as well as the instance of the database are represented by graphs. The most important browsing step in this model is the pattern step. It is based upon finding subgraphs in the instance matching a pattern and supplied with a browsing condition that links it to previous steps. This allows the user to visually specify a browsing step based upon the results of previous steps. Other browsing steps and operators in the model allow the user to randomly select some subgraphs found by a step, replace an old browsing step with a new one or undo some of the last browsing steps. After presenting the model we compare its expressive power with that of the relational algebra. 1 Introduction This paper introduces a browsing model. Browsing provides a means to investigate the contents of a database in a special way. It adds to querying the possibi...