tailieunhanh - Báo cáo khoa học: "Semantic Information Preprocessing for Natural Language Interfaces to Databases"

An approach is described for supplying selectional restrictions to parsers in natural language interfaces (NLIs) to databases by extracting the selectional restrictions from semantic descriptions of those NLIs. Automating the process of finding selectional restrictions reduces NLI development time and may avoid errors introduced by handcoding selectional restrictions. | Semantic Information Preprocessing for Natural Language Interfaces to Databases Milan Mosny Simon Fraser University Burnaby BC V5A 1S6 Canada mosny@ Abstract An approach is described for supplying se-lectional restrictions to parsers in natural language interfaces NLIs to databases by extracting the selectional restrictions from semantic descriptions of those NLIs. Automating the process of finding selectional restrictions reduces NLI development time and may avoid errors introduced by handcoding selectional restrictions. 1 Introduction An approach is described for supplying selectional restrictions to parsers in natural language interfaces NLIs to databases. The work is based on Linguistic Domain Theories LDTs Rayner 1993 . In our approach we propose a restricted version of LDTs RLDTs that can be normalized and in normalized form used to construct selectional restrictions. We assume that semantic description of NLIs is described by such an RLDT. The outline of the paper is as follows. Section 2 provides a brief summary of original LDTs illustrates how Abductive Equivalential Translation AET Rayner 1993 can use them at run-time and describes RLDTs. Sections 3 and 4 describe offline processes - the normalization process and the extraction of selectional restrictions from normalized RLDTs respectively. Section 5 contains discussion including related and future work. 2 LDT AET and RLDT LDT and AET. LDT was introduced for a system where input is a logical formula whose predicates approximately correspond to the content words of the input utterance in natural language lexical predicates . Output is a logical formula consisting of predicates meaningful to the database engine database predicates . AET provides a formalism for describing how a formula consisting of lexical predicates can be tranlsated into formula consisting of database predicates. The information used in the translation process is an LDT. A theory r contains horn clauses V P1 A A Pn- Ọ or .