Research On Controlled Vocabulary In The Web Information Service

Web information service (WIS) establishes an ordered cyberspace with knowledge organization system and standard operations. Controlled vocabulary (CV) is an symbolic concept identify system to link internets human spiritual world and real world. Information linking built by CV present the subject characteristics of information entities over internet. CV acts as information browsing tool and retrieval refining device therefore refresh and deepen user's knowledge horizon.Application of CV can be divided into function level and technical level with corresponding standard in the WIS. Function level of CV consists of browsing and searching. Classification system is used to build browsing structure according information content, Sometimes the hierarchy of classification should be limited to 3-5 to simplify the browsing. Subject lists promote the echoness of retrieval and filer the robot's harvesting. Posteriori lists can also promote preciseness of retrieval.CV refines the semantic demands with cost-effective method.CV can be viewed as digital object to enable information entities self-description. Its technical framework can be divided into data leveU protocol level and application level. Thesaurus should be coded with XML while classification should follow IS02788 and ISO5964.MARC can be converted to XML/RDF.HTTP will continue to play the main role on the protocol level while Z39.50 can be used to construct thesaurus database with Zthes profile. WHOIS++ do good to integrate searching with query routing facility. CV can build intelligent link on the base of reference linking with subject resolve over DOI and URI. Metadata registry of CV enable automatic information discovery. Thesautus item unit the information granularity to integrate data, protocol and logistic in the Web service framework.Application model of CV is categorized into tensely searching, tensely browsing, loosely searching and loosely browsing.The author constructs an experimental WIS platform with Linux, information service software package and extended software package. ROADS is recommended to help Chinese subject gateways to enhance their browsing and searching functions. Quality and simplicity is the basic feature of subject gateway comparing with search engine. It should be considered about resource selection creteria, metadata description and information discovery policy to guarantee information quality.This dissertation has 47 figures, 28 tables ,12 cases and 7 appendix.