The CIMI Profile
Release 1.0H

A Z39.50 Profile for
Cultural Heritage Information

 

 

 

 

 

 

 

 

 

Prepared by

Consortium for the Computer Interchange of Museum Information (CIMI)
CIMI Z39.50 Working Group

William E. Moen
CIMI Z39.50 Project Manager

<wemoen@jove.acs.unt.edu>
School of Library and Information Sciences
University of North Texas
Denton, TX 76201
940-565-3563

November 1998

 


Table of Contents

Preface
1. Non-Technical Overview of Z39.50 for the CIMI Profile
2. Introduction to the Profile
3. Background
4. Scope and Field of Application
5. Definitions
6. References
7. Z39.50 Specifications
7.1. Protocol Version
7.2. Z39.50 Objects
7.3. Communication Services
7.4. Z39.50 Services
7.4.1. Init
7.4.2. Search
.4.2.1. Attribute Sets
7.4.2.2. Named Result Sets
7.4.2.3. Date Searching
7.4.3. Retrieval
7.4.3.1. The Retrieval Record: An Overview
7.4.3.2. Tag Types
7.4.3.3. The CIMI Tag Set
7.4.3.4. The CIMI Schema
7.4.3.5. The Abstract Record Structure for the Retrieval Record
7.4.3.6. Constructed Datatypes
7.4.3.7. Element Set Names
7.4.3.7.1. Element Set Name b
7.4.3.7.2. Element Set Name mb
7.4.3.7.3. Element Set Name f
7.4.3.8. Unique Identifiers
7.4.3.9. Guidance for the Retrieval Record
7.4.3.10. Record Syntaxes
7.4.3.11. Use of GRS-1
7.4.3.12. Encoding Documents in a GRS-1 Record
7.4.3.13. Retrieval of Images
7.4.4. Close
7.5. Diagnostic Messages
7.6. Conformance
7.6.1. Interoperability with Other Z39.50 Implementations: Bib-1 and USMARC
7.6.2. Conformance Level 0
7.6.3. Conformance Level 1
7.6.4. Conformance Level 2
7.6.5. Conformance Level 3
7.6.6. Conformance Level 4

Appendix A -- CIMI-1 Attribute Set
Appendix B -- CIMI-1 Attributes & Attribute Combinations
Appendix C -- Semantics for Use Attributes and Schema Elements
Appendix D -- Dublin Core Mapping to USMARC
Appendix E -- Members of the CIMI Z39.50 Working Group (1995-1998)


Preface

The CIMI Profile, Release 1.0H: A Z39.50 Profile for Cultural Heritage Information [6] is the result of two separate but collaborative efforts to investigate the use of ANSI/NISO Z39.50 for use in search and retrieval of cultural heritage information by the Consortium for the Computer Interchange of Museum Information (CIMI) and the European Aquarelle Project.

The U.S. National Endowment for the Humanities funded CIMI's Project CHIO (Cultural Heritage Information Online) in 1995 as a demonstration project for using Z39.50. The CIMI Z39.50 Working Group brought together a broad range of Z39.50 experts, experts in museum systems and museum information resources, software developers, and commercial vendors. Appendix D contains a list of the participants in the Z39.50 Working Group from 1995-1998. Their commitment to the vision and possibilities of distributed search and retrieval of cultural heritage information, and their willingness to contribute time and resources to make that vision concrete, made possible the development of the original CIMI Profile (Release 1.0, March 1998) [5]. (Note: Citations for documents referenced in the Profile are in Section 6. References.)

Included in the Working Group were representatives from a number of projects, organizations, and companies that were instrumental in testing the CIMI Profile specifications through the CIMI Z39.50 Interoperability Testbed. Participants in the testbed included: Blue Angel Technologies (US), Canadian Heritage Information Network (Canada), Center of Excellence for Research in Computer Systems (Taiwan), Crossnet Systems Ltd. (UK), Databasix Information Systems (Netherlands), ELISE/DeMontfort University (UK), ELISE/Tilburg University (Netherlands), Finsiel, S.p.A. (Italy), Information Systems and Software Technology Group of the Institute of Computer Science of the Foundation for Research and Technology (Greece), Intermuse Willoughby Associates, Ltd. (US), Joanneum Research Center (Austria), System Simulation Ltd. (UK), and the University of California, Division of Library Automation (US).

The Aquarelle Project was supported by the Telematics Application Programme of the European Union. The Project based its work on an early draft of the CIMI Profile and extended its specifications to respond to the requirements of Aquarelle. These extensions were documented in the Aquarelle Z39.50 Profile [15]. Several members of the Aquarelle Project also participated in the CIMI Z39.50 Working Group. The Profile described in this document harmonizes the specifications of the original CIMI and Aquarelle Profiles.

CIMI assumes overall responsibility for the maintenance of the Profile. CIMI serves as Editor of the Profile. The CIMI Z39.50 Working Group serves in an advisory capacity to the Editor. The Profile will evolve in response to application needs and requirements of the cultural heritage information community and implementors of the CIMI Profile.

For more information about CIMI and the CIMI Profile, visit the CIMI website [4] or contact:

John Perkins
CIMI Executive Director
<jperkins@fox.nstn.ca> or <admin@cimi.org>
voice: +1-902-826-2824
fax: +1-902-826-1337


1. Non-Technical Overview of Z39.50 for the CIMI Profile

The CIMI Profile, Release 1.0H: A Z39.50 Profile for Cultural Heritage Information is a set of technical specifications for using ANSI/NISO Z39.50-1995, Information Retrieval (Z39.50): Application Service Definition and Protocol Specification [13], to search and retrieve cultural heritage information. Cultural heritage broadly defined includes art, architecture, cultural history, and natural history. Z39.50 is a standard computer-to-computer protocol for information retrieval that specifies communications between a client and server for purposes of searching and retrieving of information. A profile is a technical document and uses the formal vocabulary of Z39.50 in its specifications. Because of the technical language in this Profile, the functionality supported by the Z39.50 specifications may not always be clear. The purpose of this section is to provide an overview of that functionality in terms that do not require familiarity with Z39.50.

A profile can be understood as a set of technical specifications that govern the interaction of clients and servers for information retrieval from one or more distributed repositories. The CIMI Profile defines specifications for searching a database, selecting information to be retrieved from the database, and structuring and packaging of the information to transfer from the server to the client. The Profile contains sections that detail the way Z39.50 is used for:

The following sections provide additional details about the functionality supported by the Profile for search and retrieval and explain the specifications for search, selection, and transfer.

Search

A Z39.50 attribute set specifies access points for a given application or domain. This Profile's application area is cultural heritage information. Therefore, appropriate access points are those that address searching cultural heritage information resources such as museum object record databases and image databases. Searches often consist of a search term and information about that term. For example, a user interested in searching for paintings by Van Gogh will want to express that search in such a way that the system knows to treat the search term "Van Gogh" as "person in the role of artist" and not as "subject of a painting." To allow a user to search multiple databases associated with one or more servers, it is necessary to standardize the expression of the search so that a client and server can communicate unambiguously. This is accomplished by defining an attribute set that identifies a list of access points and additional information used to characterize search terms and express a query in a standard way. Associated with the development of the original CIMI Profile was the definition of the CIMI-1 Attribute Set (see Appendix A). This Profile references CIMI-1 for expressing searches for cultural heritage information.

The CIMI-1 Attribute Set also reflects emerging agreements within the broader museum community on a set of access points systems should support. By examining existing community standards and existing production systems, and conducting an analysis of questions that users asked of museums [8], CIMI derived a standard list of access points (in the form of the Use Attributes in CIMI-1).

CIMI-1 provides the mechanism for the client and server to share a common understanding, or lingua franca, for purposes of searching. When a user submits a search, for example, on provenance information, a server's database may or may not have provenance as a single access point, and it is up to the server implementor to map a search on provenance to the appropriate local database fields or indexes. A server that supports the this Profile can understand when it receives a search for "provenance" because the search is represented and expressed in the standard form of the CIMI-1 Attribute Set.

To address cross-domain searching, the Profile utilizes the Dublin Core Metadata Element Set [17]. Use Attributes associated with the Dublin Core elements can express a search in terms of access points represented or characterized by the Dublin Core elements.

Selection

For meaningful and useful retrieval of information from multiple databases, two requirements exist. First, the clients and servers must be able to interchange the database records (or elements from the database records) in formats they both can understand and process (see Transfer section below). Second, clients and servers need to share an understanding of the elements in those databases and be able to identify those elements unambiguously to select information to be retrieved.

A Z39.50 profile defines in a schema a list of elements likely to exist in actual databases. Each database reflects the needs of a local organization in terms of naming practices for database fields and their structure. The schema provides an abstract view of these databases. In this abstract view, database fields are enumerated as schema elements. Each element has a unique name, a unique numeric label, and a definition. A schema also shows the structural organization of those elements in an abstract record structure.

Similar to the CIMI-1 Attribute Set discussed above, the CIMI Schema and associated abstract record structure serve as the lingua franca for communication between the client and server for purposes of retrieval. The CIMI Schema abstractly identifies the units of information that may be found in a database of object records, images with associated text, and cataloging records. The schema does not dictate how a field is named in a database. Instead, it provides a standard way of referencing those elements or fields. For example, the CIMI Schema defines an element dateOfOrigin. A local database might have one or more fields related to the "date an object was created." Since semantics are provided for each of the CIMI schema elements (see Appendix C), an implementor knows that when a client requests the element dateOfOrigin, the unit(s) of information related to "date an object was created" should be returned.

The client can request groups of database fields to be returned. This is done through the use of element set names. This Profile defines several element set names (see Section 7.4.3.7.). Each element set name is an identifier for a set of elements that the server should return to the client. The Profile defines an element set name that includes the pertinent elements to enable a client to create from a database record a tombstone (i.e., essential information about an object from the perspective of a museum). The client can also request that the server return the entire database record.

The server, using the standard list of elements defined in the Schema, labels all the units of information retrieved from the database record. Upon receipt of the record, the client can then manipulate and arrange the individual units of information appropriate to users of that client system (e.g., presenting captions in local language).

Two important retrieval features of this Profile are that it specifies how to return:

1) images (e.g., digitized photographs, audio clips, etc.)
2) preformatted data (e.g., records in Standard Generalized Markup Language).

Specifications in the Schema and associated abstract record structure allow a server to return one or more images associated with an object record. Since a local database may hold the image in more than one resolution (e.g., thumbnail and high-resolution), the Profile introduces the notion of rendition. A rendition represents a specific version of the image. Therefore, the server can return to the client one or more images as well as one or more renditions of each image. In addition, specific descriptive information can be retrieved for each image and for each rendition.

Transfer

The CIMI Schema and associated abstract record structure prescribe how the database elements/fields can be labeled unambiguously by the server. Transferring the elements from the server to the client requires one more set of specifications. Z39.50 uses the concept of record syntax to address how the server packages up the database elements to return to the client. The record syntax prescribes how the server will format the database elements/fields for transfer to the client. The Z39.50 Generic Record Syntax (GRS-1, see Section 7.4.3.11.) allows the server to handle arbitrarily structured data, and GRS-1 is the record syntax required by this Profile. To support interoperability between libraries and museums, the Profile also provides guidance for using USMARC as a record syntax.

The CIMI Schema can be used outside of Z39.50. While it is out of scope for this Profile, it is possible to construct and return database records that follow the CIMI Schema in other formats such as Extensible Markup Language.

Summary

The CIMI Profile reflects a set of specifications for the use of Z39.50 for search and retrieval of cultural heritage information. It also provides two important areas of standardization that can be useful outside of the the Z39.50 application environment.

First, the CIMI-1 Attribute Set defines a large set of access points that can be used to express searches for cultural heritage information. Because this list of access points was derived by empirical investigation and discussion with members of the community, it can be viewed as representing a common set of access points useful in the cultural heritage information environment.

Second, the CIMI Schema provides a standard list of database elements and an organization of those elements for interchanging cultural heritage information. The standard list can be used as a translation device or metalanguage for labeling local database elements and interchanging those elements with other systems.

Z39.50, as a computer-to-computer communications protocol, uses these structures to enable interoperable search and retrieval of information. In the context of the cultural heritage information application, the Profile specifies how to use the lingua franca of attributes and schema elements for robust information retrieval through Z39.50.

2. Introduction to the Profile

The CIMI Profile, Release 1.0H: A Z39.50 Profile for Cultural Heritage Information (hereafter referred to as the CIMI Profile) describes and specifies the use of ANSI/NISO Z39.50-1995, Information Retrieval (Z39.50): Application Service Definition and Protocol Specification [13] in applications that include searching and retrieving cultural heritage information. Cultural heritage information resources include art, architecture, cultural history, and natural history. The Profile includes specifications for using Z39.50 in such applications, although specifications referenced in the Profile (e.g., the CIMI-1 Attribute Set for searching cultural heritage information), may have utility outside of Z39.50 implementations.

3. Background

CIMI initiated a demonstration project in 1995 funded in part by the U.S. National Endowment for the Humanities to enable users to search for and retrieve cultural heritage information from disparate and distributed information systems, including museums, image banks, libraries, etc. During 1995-1997, CIMI explored the utility of Z39.50 to search and retrieve museum information captured in digital form (e.g., object records and images). It demonstrated how Z39.50 offers solutions to the difficulties in achieving meaningful online search and retrieval of museum information of different types and structure (e.g., structured records, full-text documents, images) regardless of the hardware and software used to store the data or search for it.

To implement Z39.50 in this application, the CIMI Z39.50 Working Group developed the CIMI Profile. The Working Group consisted of Z39.50 experts, experts in museum systems and museum information resources, software developers, and commercial vendors. CIMI issued the CIMI Profile, Release 1.0, in March 1998 [5] that included specifications reflecting the consensus of the CIMI Z39.50 Working Group, input from a range of stakeholders, and practical implementation experience through the 1997 CIMI Z39.50 Interoperability Testbed. The development of the original CIMI Profile and the experience during Project CHIO are documented in the final report to the National Endowment for the Humanities. Information about CIMI's Z39.50 work is available on the CIMI website [4].

In parallel with the CIMI work, the European Union through its Telematics Application Programme funded a research and development project called Aquarelle. The Aquarelle Project shared CIMI's goal of exploring the use of Z39.50 for searching and retrieving cultural heritage information. Aquarelle used a draft version of the CIMI Profile for its system, and extended the specifications for its requirements. The result was the Aquarelle Z39.50 Profile [15].

CIMI and Aquarelle have cooperated in the past several years during the separate research and development efforts, including shared participants in both projects. A shared goal was the production of a single Z39.50 profile that would serve the cultural heritage information communities' requirements for search and retrieval. This document, the CIMI Profile, Release 1.0H: A Z39.50 Profile for Cultural Heritage Information, contains a harmonized set of Z39.50 specifications based on the CIMI and Aquarelle Z39.50 Profiles.

4. Scope and Field of Application

The Profile specifies a subset of Z39.50 features, options, and parameters needed to support functional and user requirements for search and retrieval of cultural heritage information. Z39.50 clients supporting this Profile (i.e., CIMI-clients) will be able to interconnect with any Z39.50 server supporting this Profile (i.e., CIMI-servers). CIMI-clients will behave in a manner that allows interoperability with a CIMI-server. Clients that support Z39.50 but do not implement this Profile (e.g., existing bibliographic Z39.50 clients) will be able to access CIMI-servers but with less than the full functionality provided by this Profile. Section 7.6. defines several conformance levels to enable predictable interoperability between CIMI-clients and CIMI-servers supporting this Profile.

The Profile provides specifications for search and retrieval of several types of cultural heritage information resources. These resources may be held in one or more databases accessible via one or more CIMI-servers supporting this Profile or other Z39.50 implementations. A user may search these databases to retrieve digital representations of museum information such as object records and images with associated text. These representations may be compound documents comprising multimedia formats of resources.

The Profile is a companion profile to the Z39.50 Profile for Access to Digital Collections [10], which means that it specifies compatible extensions to that Profile (hereafter referred to as the Digital Collections Profile). The CIMI Profile utilizes a subset of specifications from the Digital Collections Profile, but future releases of this Profile may utilize additional specifications from the Digital Collections Profile.

The Z39.50 Profile for Cultural Heritage Information addresses intersystem interactions and information interchange between CIMI-clients and CIMI-servers, and it imposes no restrictions on user interface requirements, the internal structure of databases that contain the digital information objects, or search engine functionality.

5. Definitions

For purposes of this Profile, the following definitions apply. For definitions of Z39.50 terms and concepts not listed here, see ANSI/NISO Z39.50-1995, Information Retrieval (Z39.50): Application Service Definition and Protocol Specification [13].

Object Record. A record that provides descriptive information about a museum object or site (e.g., its component parts, measurements, weight, creation and creator, ownership, history of use, materials and techniques used in its manufacture, inscriptions, identifying numbers, historical context, rights and restrictions, credit line for display or publication). An object record enables a museum to be accountable for and to uniquely identify an object.

Profile. Specifications for the use of a particular standard (or group of standards) to support a particular application, function, community, environment, or class of information. A profile selects options, subsets, values of parameters, etc., where these choices are left open in a standard, and where these selections are necessary to accomplish identified functions. A profile may also specify aspects of client and server behavior that are beyond the scope of the base standards. Purposes of a profile include: (1) to provide a specification for vendors to build to, resulting in products that will interoperate; and (2) to provide a specification that customers may reference for procurement purposes.

Rendition. An element in the CIMI Schema that occurs for each version (e.g., differing resolutions, color-depth, and sampling rate) of an image (where image can be any type of digital resource including audio, video, and images).

Tombstone. In the museum context, a brief record that comprises sufficient elements from a database record to enable the presentation essential information about an object.

6. References

The following list contains documents with provisions which, through reference in this text, constitute provisions of this Profile. At the time of publication, the editions indicated were valid. All documents are subject to revision, and parties to agreements based on the Profile are warned against automatically applying any more recent editions of the documents listed below. The nature of references made by the Profile to these documents is that they may be specific to a particular edition. In addition, this list contains other documents that can be consulted for further information pertinent to this Profile.

[1] Art Information Task Force. (1995). Categories for the Description of Works of Art. Santa Monica, CA: Art History Information Program Publications. <http://www.gii.getty.edu/cdwa/FULLBIB.HTM>.

[2] Attribute Set Bib-1 (Z39.50-1995): Semantics. (1995, September). <ftp://ftp.loc.gov/pub/z3950/defs/bib1.txt>.

[3] Conference of European National Librarians. (1997, October 15). Z39.50 Bib-1 Attribute Set Profile for CENL, Version 1.1. <http://linnea.helsinki.fi/z3950/cenl_profile.html>.

[4] Consortium for the Computer Interchange of Museum Information. <www.cimi.org>.

[5] Consortium for the Computer Interchance of Museum Information, Z39.50 Working Group. (1998, March). The CIMI Profile: Z39.50 Application Profile for Cultural Heritage Information, Release 1.0. <http://www.cimi.org/products/cimi_products.html#THREE>.

[6] Consortium for the Computer Interchance of Museum Information, Z39.50 Working Group. (1998, November). The CIMI Profile: Z39.50 Application Profile for Cultural Heritage Information, Release 1.0H. <http://www.cimi.org/products/cimi_products.html#THREE>.

[7] Denenberg, Ray, Kunze, John, and Lynch, Denis. (1996, November). RFC 2056, Uniform Resource Locators for Z39.50. <http://info.internet.isi.edu:80/in-notes/rfc/files/rfc2056.txt>.

[8] Janney, Kody and Sledge, Jane. (1995, September). A User Model for CIMI Z39.50 Application Profile. <http://www.cimi.org/documents/Z3950_app_profile_0995.html>.

[9] Library of Congress. (n.d.). ATS-1 Profile. <http://lcweb.loc.gov/z3950/agency/profiles/ats.html>.

[10] Library of Congress. (1996). Z39.50 Profile for Access to Digital Collections. <http://lcweb.loc.gov/z3950/agency>.

[11] Lynch, Clifford A. (1994). RFC 1729, Using the Z39.50 Information Retrieval Protocol in the Internet Environment. <http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1729.txt>.

[12] National Information Standards Organization. (1994). ANSI/NISO Z39.2-1994. Information Interchange Format. Bethesda, MD: NISO Press.

[13] National Information Standards Organization. (1995). ANSI/NISO Z3950-1995. Information Retrieval (Z39.50): Application Service Definition and Protocol Specification. Bethesda, MD: NISO Press. Electronic version of Z39.50 available at the Z39.50 Maintenance Agency. <http://lcweb.loc.gov/z3950/agency>.

[14] Network Development and MARC Standards Office. (1997). Dublin Core/MARC/GILS Crosswalk. <http://lcweb.loc.gov/marc/dccross.html>.

[15] System Simulation Ltd. (1998, May 15). Aquarelle Z39.50 Profile, Revision 1.22. <http://www.cimi.org/documents/aqua_profile_0598.html>.

[16] USMARC Format for Bibliographic Data. Washington, DC: Library of Congress, Cataloging Distribution Service. See also <http://lcweb.loc.gov/marc/>.

[17] Weibel, S., Kunze, J., Lagoze, C., Wolf, M. (1998, September). RFC 2413: Dublin Core Metadata for Resource Discovery. <ftp://ftp.isi.edu/in-notes/rfc2413.txt>.

[18] Z39.50 Maintenance Agency. <http://lcweb.loc.gov/z3950/agency>.

[19] Z39.50 Maintenance Agency. TagSet -G and -M Elements. <http://lcweb.loc.gov/z3950/agency/defs/tag-gm.html>.

[20] Z39.50 Maintenance Agency. Unit Definitions for Z39.50. <http://lcweb.loc.gov/z3950/agency/defns/units.html>.

[21] Z39.50 Maintenance Agency. Z39.50 Date/Time Definition. <http://lcweb.loc.gov/z3950/agency/defs/date.html>.


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