Bernd Wondergem

Towards an Axiomatic Aboutness Theory for Information Retrieval

In order to improve IR techniques, a detailed study of matching in IR systems is needed. This would allow us to evaluate, the way IR systems compute aboutness of documents with respect to queries.

Matching Index Expressions for Information Retrieval

The INN system is a dynamic hypertext tool for searching and exploring the WWW. It uses a dynamically built ancillary layer to support easy interaction. This layer features the subexpressions of index expressions that are extracted from rendered documents. Currently, the INN system uses keyword based matching. The effectiveness of the INN system may be increased by using matching functions for index expressions. In the design of such functions, several constraints stemming from the INN must be taken into account. Important constraints are a limited response time and storage space, a focus on discriminating (different notions of) subexpressions for index expressions, and domain independency. With these contextual constraints in mind, several matching functions are designed and both theoretically and practically evaluated.

Nesting and defoliation of index expressions for information retrieval

Abstract. In this article, a formalisation of index expressions is presented. Index expressions are more expressive than keywords while maintaining a comprehensible complexity. Index expressions are well-known in Information Retrieval (IR), where they are used for characterising document contents, formulation of user interests, and matching mechanisms. In addition, index expressions have found both practical and theoretical applicability in 2-level hypermedia systems for IR. In these applications, properties of (the structure of) index expressions are heavily relied upon. However, the presupposed mathematical formalisation of index expressions and their properties still lacks. Our formalism is based on the structural notation of index expressions. It is complete in the sense that several notions of subexpressions and defoliation of index expressions are also formalised. Defoliation, which plays an important role in defining properties of index expressions, is provided as a recursively defined operator. Finally, two other representational formalisms for index expressions are compared to ours.

Combining boolean logic and linguistic structure

Abstract Descriptor languages with Boolean operators have often been applied for Information Retrieval (IR) and Filtering (IF). In addition, linguistically motivated descriptors, such as noun phrases and index expressions, have also proven of value for IR. However, the synthesis of logic and linguistics in one descriptor language is an open issue still. In this paper, Boolean index expressions (BIEs), combining Boolean logic and linguistic structure, are proposed as a good balance between expressiveness and practical issues. BIEs provide several favourable properties as descriptor language for IR and IF: BIEs are comprehensible, expressive, compact, and tractable.

Breaking the rules. Ir and Business

The emergence of advanced information retrieval technologies has caused a drastic change in business models, in the nature of information intermediaries and in its automated processing. The characteristics of these changes and their economic consequences are analyzed.

Cumulative Duality in Designing Information Brokers

The focus of this paper is information brokers within Information Discovery (ID). We describe Cumulative Duality matrices, an instrument to deal with design criteria for such information brokers. ID is the synthesis of Information Retrieval and Information Filtering, where information brokers act as middle-agents. There are numerous design criteria for information brokers. Since these stem from ID, they exhibit a dual nature. The duality of the criteria is shown to be cumulative. In the form of a matrix, cumulative duality can be used as a design instrument for information brokers.