The START natural language system (SynTactic Analysis using Reversible Transformations) consists of two modules which share the same Grammar. The understanding module analyzes English text and produces a knowledge base which incorporates information found in the text. Given an appropriate segment of the knowledge base, the generating module produces English sentences. A user can retrieve the information stored in the knowledge base by querying it in English. The system will then produce an English response. (See Katz, 1990)
In addition, by annotating free-form text with English phrases and sentences, then matching these annotations with incoming queries,the power of sentence-level natural language processing can be effectively put to use in the service of information retrieval. Furthermore, this technique generalizes easily to the indexing and retrieval of all types of information, whether or not these are based on text. (See Katz, 1994)
The START natural language system was demonstrated at the conclusion of Voyager's Grand Tour of the outer planets, as the spacecraft sent back images of Neptune and discovered new moons and rings around the planet. During the encounter, researchers from the Jet Propulsion Laboratory and members of the press in the JPL press room were able to use the START system to retrieve information concerning the encounter, the Voyager spacecraft, and the solar system.