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Bicentennial Conference  on 
        Bibliographic Control for the New Millenium: Confronting the Challenges of Networked 
        Resources and the Web
sponsored by the Library of Congress Cataloging Directorate
Topical Discussion Group 5:
What Can the Library Community Offer in Support of Semantic Interoperability?
Discussion Facilitator:
Mary Charles Lasater
Authorities Coordinator
Vanderbilt University
Nashville, TN 37240


The Conference topical discussion groups are for the purpose of identifying recommendations made by the speakers and commentators in their presentations and for developing recommended actions and an overall action plan for discussion and approval by the Conference in its concluding plenary session. Each topical discussion group consists of a facilitator who, with a designated number of participants, is assigned a specific topic related to the presentations that will serve as the focal point for identifying recommendations and deriving recommended actions and an overall action plan. Each group will also have an LC staff member to take notes and capture highlights throughout the discussion.


Several of the papers presented at this Conference refer to interoperability as a key issue in the identification and retrieval of networked resources. In his paper on Z39.50, William Moen underscores the importance of interoperability in achieving successful searches, and articulates the particularly difficult challenge presented by semantic interoperability. . According to the report of the National Academy of Sciences (NAS) LC21: A Digital Strategy for the Library of Congress ( it is in the area of semantic interoperability where the knowledge organization and classification expertise of LC and the library community in general have the most to offer. By semantic interoperability, the report is referring to the extent to which different metadata schemes express the same semantics in their categorization (i.e., their labels for various fields). For example, when do elements have the same meaning? Is Principal Investigator , one of elements in the TEI (Text Encoded Initiative) metadata scheme, the same as Creator in the Dublin Core scheme and Author in AACR2 or, rather, is it equivalent to them? And what is meant by equivalence? These predicaments illustrate that semantic agreement among elements is required if users are to successfully and seamlessly discover and access networked resources across multiple domains. In the mid 1990s, mappings or cross-walks were created to determine this agreement. These were a useful mechanism at the time as there were essentially MARC and only a few prominent metadata schemes in place. In the past half decade, this situation has changed dramatically with the emergence of the EAD (Encoded Archival Description), the VRA (Visual Resources Association) Visual Document Description Categories, and the DGM (Digital Geospatial Metadata), among an ever growing multitude of specialized schemes. How many more such schemes will be developed we can only speculate, but the phenomenon has made it difficult to continue to apply this mechanism effectively. The problems are many and varied, but may be usefully identified as: structural interoperability, syntactic interoperability, and semantic interoperability. All three areas have involved the participation and cooperation of the library and metadata communities. It is clear that considerable work remains to be done on the problematic issues surrounding metadata interoperability.

Another kind of semantic interoperability (i.e., semantics of the contents of fields) is expressed by Lois Chan. In her paper on exploiting library subject and classification tools to retrieve networked resources she cites the prime importance of interoperability in enabling users to search among resources from a multitude of sources generated and organized according to different standards and approaches. Barbara Tillett in her paper on authority control on the Web notes a proposed experiment within IFLA (International Federation of Library Associations) that will require the exploration of ways to provide interoperability across multiple authority files. Thomas Mann argues that LCSH provides the heavy lifting capabilities needed by research libraries. Perhaps controlled vocabulary can be used to bridge subject aspects of metadata schemes. Researchers at OCLC, particularly Diane Vizine-Goetz, are undertaking extensive research with DDC is attempting to provide a possible classification bridge. The NAS report also mentions that LC, and by implication the library community, has much it can contribute by virtue of its extensive cataloging experience and its unique understanding of entity-relationships that are at the root of interoperability mechanisms. Can LCSH, LCC and DDC be used to enhance resource organization and discovery on the Web? How can known authority control mechanisms be used or enhanced to provide "interoperability"?


In this assignment we are asking you to develop a list of 4-6 recommended approaches that the library community from its unique perspective could offer towards advancing semantic agreement among multiple domain-specific metadata schemes. Such approaches might exploit library tools, resources, and practices. They might also iterate the use of mechanisms to further knowledge representation or to extend entity relationship modeling. A list of approaches would be of obvious value to the metadata community, particularly such groups as the Dublin Core and the INDECS communities who are seeking common ground in the expression of metadata for networked resources. The list could also serve in the development of common standards for metadata interoperability. From the library perspective, such a list could serve to affirm the profession's leading role in the development and promotion of resource description and discovery standards.


Your topical discussion group is organized into two parts to cover the two Conference days in which you meet.

  1. The first meeting is in the afternoon of Day 2 of the Conference. The objective of this meeting is to have you brainstorm your topic by sharing your thoughts and ideas in an informal discussion. Your facilitator will serve to direct the discussion and to keep it focused and moving. An LC staff member will be present to record major points of discussion.

    Follow the lead of your facilitator in determining the format of the discussion. Then start by identifying any suggestions or recommendations offered by the speakers, commentators, and participants on your topic. In addition to the papers noted above, was there any further discussion of semantic interoperability in any of the other papers? Next, move on to identify possible approaches that the library community might offer to advance semantic agreement among various domain-specific metadata schemes. Discuss the purpose of these approaches and the context in which they would be most effective. By close of the meeting, you should have an extended list of approaches along with their purpose and contexts to review on the following Day 3 of the Conference.

  2. The second meeting begins in the morning of Day 3 with the facilitator and LC recorder present. Time spent at this meeting is focused on reviewing the list of approaches drafted in the first meeting and extracting from it a list of 4-6 recommended approaches, together with their purpose and contexts, arranged in priority order. In the course of determining this list, consider these questions:
    1. Does the list identify specific approaches that would help advance semantic interoperability among the many and various metadata schemes?

    2. Does the list state the purpose of these approaches and the contexts in they would be most effective?

    3. Are the unique experience and expertise of the library community reflected in the approaches, particularly in the areas of knowledge organization and classification?

Once you have finalized the prioritized list of criteria, the LC recorder will input it to a computer and a Powerpoint presentation will be created for your facilitator to present to conferees.

Presentation and Action Plan:

Your facilitator will present the prioritized list of approaches for discussion and approval in the closing session of the Conference. Conferees will use this list along with the prioritized recommendations presented by the facilitators of the other topical discussion groups to develop an overall action plan that LC can carry forward from the Conference.

Library of Congress
October 22, 2000
Library of Congress Help Desk