A Word Database for Natural Language Processing

A Word Database for Natural Language Processing Brigitte Barnett Hubert Lehmann Magdalena Zoeppritz IBM Scientific Center, Tiergartenstral3e 15, 6900 Heidelberg, Federal Republic of Germany Abstract: The paper describes the design of a fair sized lexi- cal database that is to be used with a natural language based expert system with German as the language of inte- raction. Sources for entries and tools for constructing and maintaining the database are discussed, as well as the in- formation needed in the lexicon for the purposes of syntactic and semantic processing. 1 Introduction The intent of this paper is to show some aspects of a com- puter dictionary geared towards the natural language com- ponent of an expert system. The dictionary is organized as a database to integrate tile various aspects of lexicographic work and, at the same time, enable fast access from a parser. Work on the lexicon was long neglected - both in theoretical linguistics and natural language processing projects - so we felt that a principled approach was overdue (cf. Sedelow (1985) for a survey of related work). In the past two years, we concentrated therefore on the formulation of criteria for establishing syntactic features which have to be coded in the lexicon, and we will report here on some of our findings. This will be preceded by a brief overview of the aims of our overall project and a short description of the prototype sy- stem we are building. We will then describe the design of our lexicographic database including the criteria for selecting sources of the vocabulary and some of our tools for editing and querying. The main objectives of the project Linguistics and Logic Based Legal Expert System, which is a Joint Research Pro- ject between the University of T/ibingen and the IBM Scientific Center Heidelberg, are to design and implement a natural language based knowledge acquisition and query system and to build a legal expert system on its basis. It consists of the following components: • The dialog component controls the interaction with users and contains among other things an explanation compo- nent and a component for preparing system output for display and for eventually generating natural language explanatory texts. In a so-called user profile, as much information about a user is kept as necessary: to improve answers and ex- planations, one must know certain things about the user, mainly about her or his knowledge in current sessions. For example, one may want to avoid explanations about details the user already knows. • The deductive component is activated by user queries, by input of new knowledge, and by requests of the Natural Language Analyzer. • The knowledge manager administers the actual know- ledge base in the working area as well as its permanent version in the database. It is the only component allo- wed to update the permanent knowledge base. It loads knowledge from the database into storage and requests consistency checks for new knowledge. With the excep- tion of the lexical database, the Knowledge Manager …

Content truncated to 500 words