Natural-Language Interface

Natural-language (NL) interfaces built so far have primarily addressed the problem of accessing information stored in conventional data base systems. Among the proven capabilities exhibited by these systems are those that: • Provide reasonably good NL access to specific data bases • Access multiple, remote data bases. • Answer direct questions. ( "What is Smith's salary?") • Coordinate multiple files. ( "Wha t is Smith's loca t ion?" translates into "W ha t is the location of the depar tment of Smith?.") • Handle simple uses of pronouns. • Handle many elliptical inputs. ( "Where is John? Sam?") • Do basic report generation. ( "By sex and age, list the salary and title of employees in New York.") • Extend linguistic coverage at run time. (Define " J D " as " Je f f e r son Davis Jones" Le t "Q1 Smith salary" be like "What is the salary of employee Smith? . . . . Q1 JD A G E ? " ) • Analyze NULL answers. ( " H o w many Japanese carriers have inoperative air search radar?" Response: "The re are no Japanese carriers.") • Restate in English the system's in terpreta t ion of inputs. ~. Correct spelling errors. • Enhance the data in a data base with special-purpose functions. (E.g., calculate distances between cities.)