We are establishing a spoken language interface to an Official Airline Guide (OAG) Database, to which the general public could eventually book air tickets directly with computer databases (including over the telephone). It consists of two ATIS (Air Travel Information System) natural language systems (a full linguistic system and a keyword-based robust system), an SQL (Standard Query Language) generator, a speech recognizer, a speech synthesizer, a text generator, an N-best algorithm and an N-best interface. This paper describes three of our successfully developed modules: (1) the full linguistic ATIS natural language system which can process not only an isolated imperative, question, assertion, but also a complete booking scenario; (2) the SQL generator which has been connected to the full linguistic system to realize generic public transactions with a computer database through natural language sentences; (3) the N-best interface which guarantees that the full linguistic system will accept N sentence candidates sent from the speech recognizer. It also connects the full linguistic system with the robust system.

Keywords: Natural Language Processing, Spoken, Language System, Syntax, Semantics, Pragmatics