In this paper we show that in advanced information retrieval (IR) applications capa- bilities for data aggregation, transitive computation and NF 2 (non-first normal form) relational computation are often necessary at the same time. We demonstrate that complex objects are naturally modeled as NF 2 relations whereas structures like hi- erarchical thesauri must be modeled for transitive computation. Transitive process- ing cannot be supported by stmcturally static structures like NF 2 relations. We pres- ent a truly declarative query interface, which integrates data aggregation, transitive computation and NF 2 relational computation. Thus the interface supports the re- trieval and structural manipulation of complex objects (e.g., documents, and biblio- graphic references), their retrieval through transitive relationships (e.g., thesauri, citations) and data aggregation based on their components (e.g., citation counts, author productivity). Most importantly, users can formulate queries on a high ab- straction level without mastering actual programming or database techniques.

This article presents a novel user-oriented interface for generalized informetric analysis and demonstrates how informertic calculations can easily and declaratively be specified through advanced data modeling techniques. The interface is declarative and at a high level. Therefore it is easy to use, flexible, and extensible. It enables end-users to per- form basic informetric ad hoc calculations easily and often with much less effort than in the contemporary online retrieval systems. It also provides several fruitful generaliza- tions of typical informetric measurements like impact factors. These are based on sub- stituting traditional loci of analysis, for instance journals, by other object types, such as authors, organizations, or countries. In the interface, bibliographic data are modeled as complex objects (non-first normal form relations) and terminological and citation net- works involving transitive relationships are modeled as binary relations for deductive processing. The interface is flexible, because it makes it trivial to switch focus between various object types for infermetric calculations, e.g. from authors to institutions.

Conceptual modelling is needed to form a description of the domain of application at hand. In order to express the result of conceptual modelling, we need a modelling language. First order predicate logic (FOPL) or its variants (like Horn-clauses and Description Logics) and extensions (second order logics) can form a backbone of such a language, but some criteria is needed to define the fruitfulness or suitability of a modelling language, given the modelling task. The modelling language together with its methodology constitute a modelling perspective. Many accounts of...