Design And Implementation Of Internet Based Z39.50 Client Information Retrieval System

With the expansion of social information, the explosion of information resource and the change of information retrieval mode challenge the traditional information retrieval system. The online bibliographic retrieval service (OBRS) is a main service that should be provided by information service providers (ISP) in network environment. Each OBRS provided via Telnet or Web has its own access procedures and a special user interface and query language. The Z39.50 protocol offers a solution to heterogeneity problems.Z39.50 protocol is the standard of network information retrieval. It was developed from informatics, and has been ISO standard now. The advantage of using Z39.50 protocol to provide OBRS is that Z39.50 not only supports all kinds of advanced retrieval functions, such as the reuse of query result, but can shield the heterogeneity among every server, so as to search all the Z39.50 database with the same client retrieval system.After a detailed analysis of Z39.50 protocol and its implement mode, a system is designed and implemented with Visual Basic language in Windows environment in this paper. It is a Z39.50 client retrieval system based on TCP/W The system supports Chinese retrieval and multi-MARC (machine-readable cataloguing) including CNMARC, and is highly operable and has friendly interface. Main technical design and simple evaluation of its performance are also given in this paper.