Positioning Z39.50 in the Networked Library Standards for Building Sustainable Services William E....

Positioning Z39.50 in the Networked Library Standards for Building Sustainable Services

William E. Moen<[email protected]>

School of Library and Information SciencesTexas Center for Digital Knowledge

University of North TexasDenton, TX 72603

Texas Library Association Conference 2003, April 2, 2003 Houston, TX

Moen Texas Library Association Conference -- April 2, 2003 -- Houston, TX 2

Overview Putting Z39.50 in perspective … a bit of history Z39.50 uses and implementation in Texas The networked library Standards for building services


Where did Z39.50 come from? Vision of library leaders in the 1970s Sharing bibliographic and authority records to create

a system of national bibliographic control Linking the major bibliographic utilities via computer

network

Standards development began in 1979 A protocol to support national bibliographic control…

Searching library catalogs Exchanging authority records (Linked Systems Project) Copy cataloging


What Z39.50 was not planned for Did those library leaders envision the Internet, the

Web, and technologies of the 21st Century? Assumed a few large bibliographic systems would

use the protocol for record exchange Developed in the context of the Open Systems

Interconnection not in the context of the Internet and the Web

Widespread adoption in the library community and its integrated library systems

Use of the protocol outside of the library community


Brief history of Z39.50 Pre-1979: The vision and ideas 1979: Standards development

initiated within library community 1984: Draft standard voted down

by NISO 1988: Approval of ANSI/NISO

Z39.50-1988 1992: Approval of ANSI/NISO

Z39.50-1992 1995: Approval of ANSI/NISO

Z39.50-1995 Late-1990s: Development of

Z39.50 profiles 2002: Approval of ANSI/NISO

Z39.50-2002

1970s: Experimental Internet

Late-1980s: Libraries get connected to the Internet via Telnet

Mid-1990s: Emergence of Web as real world application

Late-1990s/Early 2000s: XML, SOAP, Dublin Core, etc…


What does Z39.50 offer? Information Retrieval (Z39.50): Application Service

Definition and Protocol Specification Allows

Searching of databases on one or more systems Retrieval of records from those system Without user having detailed knowledge of each system

Provides Search and retrieval of bibliographic and non-

bibliographic resources Technical foundation for information access and resource

sharing


What are the benefits of Z39.50? Provides single interface for information access Enables integrated access to multiple and diverse

resources Supports simple and sophisticated searching Allows flexible and customizable retrieval Provides access control mechanisms Key technology for distributed information access in

the networked environment


How is Z39.50 being used? To provide a common way to interact with databases

Serving up bibliographic records from online catalogs Serving up records from commercial databases Using a single interface to search databases

Information environments Libraries Commercial database providers Government information locators (e.g., TRAIL)

Applications Bibliographic citation software (e.g., Procite, EndNote) Portals Virtual libraries (e.g., Colorado, Illinois, Texas)


ZLOT Technology Inventory & Assessment

Category Population Served Total # Percent Responses Percent

Small 0 – 10,000 321 58.3 152 51.9Medium 10,001 - 100,000 199 36.1 119 40.6Large 100,001 or more 31 5.6 22 7.5TOTAL 551 100% 293 100%

Category Enrollment (FTSE) Total # Percent Responses Percent

Small Less than 2,000 48 32.7 21 28.0Medium 2,001 – 9,999 75 51.0 41 54.7Large 10,000 or more 24 16.3 13 17.3TOTAL 147 100% 75 100%

Public Libraries

Academic Libraries


Z39.50 servers operating in Texas

79%

58%

84%

43%

31%

47%

65%61%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

2-Year Academic Public Sample

Included

Running

Source: ZLOT Technology Inventory and Assessment Survey, 2002


Z39.50 clients operating in Texas

88%78%

68%

43% 51%57% 55%

64%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2-Year Academic Public Sample

Included

Running



How is it used in Texas libraries?

0%10%20%30%40%50%60%70%

Other

Exper

imen

tal

Patro

ns

Refer

ence

Ser

vices

Tech

nical

Servic

es

2-Year

Academic

Public

Sample



So, what’s the bad news? Early Z39.50 clients

and servers: Needed much care

and feeding Were not easy to use

Little interoperability Differences in how

vendors implemented the standard

Little consensus on how to make it work


What’s changed/changing? Problems of interoperability are better understood

Search functionality of local systems Local indexing decisions

Z39.50 profiles have been developed Detailed specifications for using Z39.50 in particular

applications• The Bath Profile: An International Z39.50 Specification for

Library Applications and Resource Discovery• U.S. National Z39.50 Profile for Library Applications• Z Texas Profile for Library Applications

Conformance to profiles by vendors and libraries Interoperability testing can help improve systems


What’s changed/changing?

Interfaces are becoming more usable


What’s changed/changing?

Number of Z39.50 accessible resources increasing


Are there alternatives to Z39.50? It depends… what application/service do you want? And there are tradeoffs… what costs are incurred? Possible alternatives

Have users search individual databases through native interfaces – web interfaces make this a bit easier

Build large repositories of metadata (e.g., OAI) Use customized translators and scripts (e.g. WebFeat) Wait for new protocols and technologies (e.g., XML

standards such as XML Query, XPath, etc.) Evolution of Z39.50 for the web environment…


ZING – Z39.50 International Next Generation Make intellectual/semantic content of Z39.50 more

broadly available Make Z39.50 more attractive by lowering barriers to

implementation Use of XML – to represent and encode data Use of HTTP – for transport Use of SOAP – for interaction between client and server

based on Remote Procedural Call (RPC) Several initiatives: ZOOM, ez39.50, ZeeRex,

SRW/UFOR MORE INFORMATION, VISIT THE PROJECT WEBSITE…

http://www.loc.gov/z3950/agency/zing/zing.html


Search/Retrieve Web Service – Overview Builds on Z39.50 and web technologies Retains Z39.50 concepts:

Results sets Abstract access points Abstract record schemas Explain & Diagnostics

Web technologies: XML, SOAP/RPC, HTTP Combines several Z39.50 features into two “operation types”

Search/Retrieve Explain

Provides a standards-based method for representing and issuing queries, and retrieving records


SRW and Classic Z39.50 Lightweight SRW clients Gateways between SRW and classic Z39.50 SRW queries should map to Z39.50 queries

CQL Z39.50 attribute combinations Retrieval records returned to SRW gateway

Transformed from a Z39.50 record syntax to XML

FOR MORE INFORMATION, VISIT THE PROJECT WEBSITE…

http://www.loc.gov/z3950/agency/zing/zing.htmlhttp://www.loc.gov/z3950/agency/zing/srwu/implementors.html


The library in the networked environment… Collections of resources – local and distributed Collaborative services and activities Tools that assist users in networked information

resource discovery and access Services that help users

answer questions, learn about the collection, learn about the bibliographic tools, and generally connect users to appropriate resources

A management structure that allocates resources and policies for inter-organization collaboration

Extends the reach and range of users


Networked library components User groups

Local, onsite Distributed, remote

Services Local Collaborative Remote

Resources Information

• Local• Distributed

Human

Technology Local applications Distributed applications Standards

Management Local Collaborative


Characterizing the networked library Virtual library components An environment for provision of

Services Resources

Not a digital library Not all resources available are in digital/electronic form

An evolving product that responds to Users’ needs Available resources Current and emerging technologies


Service-centric virtual library

UserGroups

Resources

Technology

Management

SERVICES


User-driven services

LIBRARY SERVICES

UserGroup

UserGroup

UserGroup

UserGroup

LibraryResources

LibraryTechnology


Library services for the networked library Infrastructure/internal

Collection identification, selection, and acquisition/access

Collection building and digitization

Collection organization and preparation

Inter-organization access Trust and authentication Billing and payment Preservation and archiving

Patron Resource discovery service Access service Reference service Instruction service Patron account service


Building services for the networked library What are the requirements for the services? What are alternatives for deploying the services? What technologies are available to support the

services? What standards are available? What are the tradeoffs of standards and non-

standards approaches?


Infrastructure standards -- NISO ANSI/NISO Z39.50: Information Retrieval (Z39.50): Application

Service Definition and Protocol Specification ISO 10160 & ISO 10161: Interlibrary Loan Application Service

Definition & Protocol Specification ANSI/NISO Z39.83: Circulation Interchange Protocol (NCIP) ANSI/NISO Z39.84: Syntax for the Digital Object Identifier - 2000 ANSI/NISO Z39.85: Dublin Core Metadata Element Set - 2001 ANSI/NISO Z39.88: The OpenURL Framework for Context-Sensitive

Services (2002) ANSI/NISO Z39.89:The U.S. National Z39.50 Profile for Library

Applications (2002) Networked Reference Services (standards development underway) MetaSearch Initiative (may lead to new standards activities)


Standards supporting services Each standard enables different services

Networked information retrieval (Z39.50) Automated interlibrary loan (ILL) Circulation applications (NCIP) Reference linking (OpenURL) Resource description (Dublin Core)

But they can work together to support robust and interoperable information access and resource sharing services


Opportunities and challengesSo many users, resources, technologies, standards! A service-based framework provides a context for rational

response: For choosing and developing services For identifying and selecting appropriate technologies and

standards The networked library requires more agreements and

support of standards and … Collaboration

Vendors Content providers Libraries Funding agencies

Positioning Z39.50 in the Networked Library Standards for Building Sustainable Services William E....

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