Information retrieval using a transportable natural language interface

This paper describes work in progress to develop a facility for natural language access to a variety of computer databases and database systems. This facility, called IRUS for Information Retrieval using the RUS parsing system, allows users who are unfamiliar with the technical characteristics of the underlying database system to query databases using typed English input. This system can be thought of as a stand-alone query system or as part of a management information system (MIS) or a decision support system (DSS).Many systems boast of having a "user-friendly" or "English-like" or even "English" interface so that users require a minimum of special training to use the system, but most such systems use shallow, relatively ad hoc techniques that are not robust or linguistically sound. We are using a large, well-tested, theoretically-based, general parser of English that has been developed and extended in a variety of research projects for over a decade.One of the primary emphases of IRUS is transportability, which includes three types of changes: (1) changing the domain, (2) changing data bases within the same domain, and (3) changing data base systems. The use of a general parser for English is an important part of the solution to the transportability problem, but there are other parts as well, since portions of the system beyond the parser must know the conceptual content of the domain, the way in which this is reflected in a collection of datasets, and the operating characteristics of the dbms being used to access these datasets.Other researchers have investigated similar issues [8, 5, 6, 12]. We have attacked this problem by building a knowledge-based system, with procedural components independent of domain and data base structure, directed by domain and database dependent knowledge structures. We are also building tools for conveniently creating and maintaining these knowledge structures, with an eventual goal of allowing end-users to extend and modify these knowledge structures to suit their own needs. Given this set of goals, and these tools, we consider the current implementation, which uses the System 1022 dbms on the DEC KL-2060, to be only one of a set of possible implementations, and are not constraining IRUS on the basis of 1022's strengths and weaknesses.This paper presents an overview of the IRUS system, emphasizing those aspects of the design that are critical to transportability. We describe the parsing system, which is a completely indepen