Table of Contents
Laurie Davidson, Innovative Interfaces
In this session, presenters talked about the quirks, advantages and disadvantages of using Z39.50 protocol through GuiCat (Mary Jane Kelsey) and through Millenium (Laurie Davidson).
The presentation gave a brief historical overview of the protocol. The idea arose when the union catalogs LC, OCLC, WLN and RLIN wanted the ability to search each other's catalogs. LC was appointed by NISO to be the maintainer of Z39.50 standards.
In theory and in practice, the use of Z39.50 protocol allows computers to exchange search strategies in a language of their own, so that the user never needs to leave her native interface.
Steps in using Z39.50
1. Local users searches in their usual way
2. The local Z-client translates that search into 'z-speak'
3. The remote Z-server translates the 'z-speak' into a local search query
4. Database is searched, results returned based on the indexing of the remote location
There are some caveats, however: Z39.50 does not standardize user interface. Does not compensate for local practices or authority control. Does not deliver results ranked for relevancy.
Searches go through three stages:
1. Initialization, in which parameters are set. Determines the version of Z39.50 the client is using, addresses authentication issues and some user options.
2. Search, in which attributes are determined, attribute values are matched, and a response is given to the client.
3. Retrieval, in which presentation and segmentation of results occur.
Some Bib-1 attributes were discussed:
1. Use—refers to the access point in use, which index will be searched.
2. Relation—refers to use of, for example, 'equal to', 'less than'.
3. Position—refers to which position in the field is searched.
4. Structure—for example phrase vs. word searching.
Configuration guidelines for Z39.50 can often be found on vendor web pages. Z39.50 searching offers some standardization, but it is not a panacea. There will be differences in indexing policies between databases, and differences in attributes supported. A good example is a subject search by keyword vs. a subject search by subject headings. There are also target limitations; for example, RLIN, OCLC, LC each have different strategies to bring back the best search result.
GUICAT as a Z39.50 client for Innovative allows one to limit searches and limit parameters. One can also update holdings in OCLC through a Z39.50 session. One can click to add one's holdings to OCLC if you have this setup with OCLC.
What is it good for?
—Allows for simultaneous searches of multiple foreign databases
—Great for training staff
—Avoid complexities of downloading from your utilities (in record downloads)
—Promotes some positive workflow changes
—Allows users to use the interface they are familiar with
—Z39.50 is a communication standard, BUT is not standardized yet
—Innovative has Z39.50 clients for GUICat, MillAcq, MillCat
—One can zap records into one's database from a Z39.50 server
Laurie Davidson spoke more about the potential of Z39.50, and introduced the Bath profile, an effort to further increase interoperability. The profile would list functions that must be supported, and go further to define searches (for example, what do we mean by "title search"?). The profile has three key functional areas: Bibliographic Search and Retrieval, Holdings Search and Retrieval and Cross Domain Search and Retrieval. Each of these areas is broken down into levels of conformance, Level 0 being the lowest and Level 2 the highest. Innovative anticipates full conformance to Level 0 by the end of 2001.
III users maintain their own server files. Each file has information about the server in that file as well as databases attached to that server. The files also contain the search attributes for the server.
III currently uses Version 3 of Z39.50. This means that III's Z39.50 servers operate fully with clients that use either Version 2 or Version 3 of the Z39.50 protocol.
Laurie listed URLs to provide more information about the Bath profile (http://www.nlc-bnc.ca/bath/bp-current.htm), the NISO Working Group (http://www.unt.edu/zprofile/), and the Z39.50 standard (http://www.loc.gov/z3950/agency/). She also gave a URL that lists resources for configuring Z39.50 servers, providing IP addresses and attributes, set-up information (http://www.indexdata.dk/targettest/).