Abstract:
In this thesis, a portable natural language interface system for communicating with databases in Turkish is developed. The system does a two step transformation from a Turkish query in user's view to an intermediate meaning repl'esentation language D&Q and finally to a target database language SQL. It is composed of domain independent runtime modules for different processing stages, namely language processing, internal query generation and translation to SQL. Modules refer to the knowledge base in which diverse knowledge about the domain and the database are maintained. Two additional modules, to wita spelling corrector and a history keeper are incorporated in the system. A syntactic parser is used in analyzing queries. for the syntactic parser. a formalization of a subset of Turkish grammar based on the simple principle of general categorization incorporated with the notion of modifications between words is proposed and a grammar that consists of a collection of rervrite rllles for the formal representation of sentences is discussed. A decision tree which works with suffix strip off approach is used for the morphological parsing of n.ouns. Parse trees produced for different types of sentences using the formalized grammar are given. Regarding to the meaning representation, an "intelllgent" meaning representation generator which has a rule based reasoning capability is designed. The interpretations of some modification relations are discussed in details. Finally the interpretation of a full sentence is shown. The system is tested on an imaginary stude-course-instructor database, all examples refers to this database. Possible extensions for both the parser and the meaning representation generator are also proposed at the end of the thesis.
