This paper proposes a new approach to querying collections of structured textual information such as SGML/XML documents. Knowledge about the structure of documents is an additional resource that should be exploited during retrieval since the semantics of the different textual objects can be used to specify an information need much more precisely. However, the traditional probabilistic retrieval model lacks the ability to handle structural information. We define a new retrieval function based on the probabilistic model which overcomes this drawback. The presented query language allows the assignment of structural roles to individual terms. The efficient evaluation of queries in this framework requires appropriate index structures. We design text and structure indexes and show how their information is combined during evaluation. The implementation supports additional functionalities such as a table of contents for browsing. First evaluation results show the feasibility of the approach on collections of unstructured documents. 1

This paper proposes a new approach to query collections of structured textual information like SGML/XML documents. Knowledge about structure of documents is an additional value that should be exploited during retrieval. The semantic of different text parts could be used to specify an information need much more precisely. The traditional probabilistic retrieval model lacks the ability to handle structural information. We define a new retrieval function based on the probabilistic model which overcomes this drawback. The presented query language allows the assignment of structural roles to individual terms. The efficient evaluation of queries in this framework requires appropriate index structures. We design text and structure indexes and show how their information is combined during evaluation. The implementation supports additional functionalities like a table of contents for browsing. First evaluation results show the feasibility of the approach on unstructured document colle...

. The MyView project aims at the integration of both structured and unstructured bibliographic information from a diversity of heterogeneous Internet repositories like electronic journals and traditional libraries. Based on the user's individual information need MyView maintains a personalized warehouse for bibliographic data in a unified scheme, which is locally available for browsing, ad hoc queries and analysis. This paper gives an overview of the project, emphasizes research issues and describes the current state of the implementation. 1 Introduction The recent development in multimedia technology and the growth of the World Wide Web will have profound influence on libraries of the future. Besides traditional libraries offering their bibliographic data on the Web, many research projects in the USA (Digital Library Initiative 1 ), UK (eLib Project 2 ), Germany (Global Info 3 ) and other countries (see [18]) have invested in digital library development. Nevertheless, however l...

This paper describes the SIM architecture and the techniques used to support these standards. It describes how a standard based approach can be used to support structured queries and presents the techniques used by SIM for query evaluation

Semi-structured data, including but not limited to structured documents, has speci#c characteristics and is used in ways di#erent to tabular data. SGML and XML are widely used to represent information of this type. The demands on systems that manage semi-structured data vary from those on traditional relational systems. This paper reviews the nature and characteristics of semi-structured data, and the functional needs of those applications, including query requirements, document description, manipulation, and document management needs. It examines alternative physical models for semi-structured data, and evaluates and compares alternative system architectures.