Eine integrierte Anfrageumgebung für umweltbezogene Objekte und Dokumente

Abstract

Modern Environmental Information Systems (EIS) offer access to both data residing in databases and in document repositories. However, no uniform access mechanism for both types of data is provided. Rather, database querying is mostly restricted to the filling of forms, while information retrieval is based on keyword and meta-data specifications. Internet-based EIS also provide means for navigation and/or browsing through the information collection. The implementation of many data access paradigms, as in this conventional approach, has disadvantages. The users need to get accustomed to each paradigm and have no uniform means for accessing relevant information irrespectively of its nature. The situation becomes more acute by the fact that database queries return exact results, while text retrieval engines return data ranked by relevance. Hence, users need some way of translating their exact database queries to a set of relevant terms appropriate for text retrieval. WIND, a Warehouse for INternet Data [SFR97], bypasses this problem by providing a uniform information retrieval mechanism. WIND couples the database querying paradigm, which is appropriate for structured information, with the text retrieval paradigm, which is intended for unstructured data. We present our approach by means of an example, in which the environmental data of an EIONET1 database is combined with text documents.