Z39.50 gateway for the Research Library catalog

Web access to the Research Library's online catalog uses a Z39.50 interface based on Geac Computers' Geoweb and Advance software. Z39.50 is an international standard query language which allows any Z39.50 client to search and retrieve records from any Z39.50 server. The Research Library has modified the software from Geac Computers to more readily satisfy the needs of its customers.

      The Research Library's WWW Online Catalog was introduced Feb. 3, 1997. DOE Energy and Science Technology, BIOSIS, Engineering Index, INSPEC, NTIS, and ABI/INFORM were also offered through this same interface for several years. Access is controlled through IP addresses.

      Using this interface, a searcher uses a standard Web browser (e.g., Netscape) to connect to the Geoweb gateway. The gateway displays a search form which allows the searcher to enter words or phrases to search, and to specify which field to search (e.g., title, author, etc.) . A click of a button allows the searcher to switch from a word search (find the word(s) anywhere in the specified field) or a browse search (display a dictionary-style list of terms which begin with the requested search term). Boolean searches within a field or across fields can also be entered. Clicking the Submit button sends the search request to the Geoweb gateway where it is translated into a Z39.50 query. The query is passed to the Advance Z39.50 server where it is translated again into the query language used by the Advance software. Advance is the online catalog software that the Research Library has been using since 1993. Advance takes the query, searches its databases, and returns the results to the Advance Z39.50 server. The server converts the results into Z39.50 format, and passes them back to the Geoweb gateway. Geoweb builds HTML pages to display the results and passes them to the Web browser where they are displayed.

      A feature of Z39.50 that makes it attractive for library applications is the ability to conduct an interactive session between the searcher and the online catalog. When search results are passed back to the searcher, the Z39.50 server maintains information about the session. If the searcher wishes to browse up or down in the dictionary list, Advance remembers where the search left off and is therefore able to respond to the browse request. If a searcher wishes to see the full display of records retrieved, Advance can resend the search results in a different format. If information in the record triggers an idea for a new request, the searcher can click on a hotlinked term in the record and a new browse search is sent. Hotlinks may also include URLs for other Web sites, or for PDF versions of the full article described in the record. By clicking on an external URL, the searcher can temporarily leave the Z39.50 session and, using the browser’s Back button, return to the still-active session. Clicking on the URL of a PDF file will cause the PDF article to be downloaded directly to the searcher’s computer. When the session is finished, clicking on the Exit button, will cause all session information to be deleted by the Advance server.