``Resources Metadata+User Metadata: Toward Knowledge Metadata''
Prof. Zorana Ercegovac
Department of Library and Information Science
Graduate School of Education and Information Studies
University of California, Los Angeles
Los Angeles, California 90095-1521
Email: zercegov@ucla.edu
URL: http://www.gslis.ucla.edu/LIS/faculty/zercegov/ercegovac.html, http://www.lainet.com/infoen/

Context

In order to enhance the organization of digital resources on the Internet, it might be useful to look at some of the traditional features that have been successful in organizing and describing printed resources in bibliographies and periodical indexes. Bibliographies are typically compiled and annotated by experts in a given field (e.g., Bibliography of American Imprints to 1901; The law of the sea: a bibliography). Periodical indexes (e.g., Engineering Index, Inspec) are designed to provide timely access to the periodical literature, papers presented at conferences, and parts of books. These features include Preface, Intended Users, and Instructional model of how to use a certain tool; together, they provide a rich layer of information about the collections and its uses. We believe that these techniques have not been sufficiently exploited in the context of designing metadata standards for describing large heterogeneous distributed datasets on the Web; their conceptual simplicity and complementarity to the model of library catalogs might help the user see the inner structure of the collections better than it has been possible so far, and increase the probability that only relevant objects from these collections will be retrieved.

Content metadata is not sufficient: we need user metadata

Library catalogs have served well as a primary model for many metadata standards. However, while they offer guidance in representing the contents of a given collection, they fall short of representing the user or different classes of users of virtual collections. Library catalogs, however, make several assumptions; the collection is well defined and available locally; the user typically comes to the library; and reference librarians are there to help and instruct. So, library catalogs do not have preface to their collection (note: online catalogs that are accessible remotely do), statement of intended beneficiaries, or instructional guides to teach people how to use catalogs; users' guides are relatively novel phenomenon and limited to online catalogs. Unlike library catalogs, bibliographies and periodical indexes are not limited to any particular physical collection of objects; their readers are more heterogeneous than those who use library catalogs; and typically, there are no intermediate experts to teach the user how to use a particular tool. As such, bibliographies are closer to the nature of metadata that represent digital virtual libraries than they are to library catalogs that represent local holdings. Therefore, bibliographies define the extent of their scope and domain (explicated in "preface"); specify user classes (via ``intended user''); and describe effective ways for discovering resources in virtual collections. Drawing on the model of primarily library catalogs, current metadata standards have attempted to provide the descriptive, locational, and to a certain degree collocational power. The inclusion of preface, use, and usage could extend the functionality of metadata standards beyond the objectives of traditional library catalogs; the value-added functions are contextualization, appraisal, quality control and preservation, legal control, multiple access control, and, in particular, the user complex layer.

Case study: Putting the user in center

The user complex layer is being incorporated into Learning Portfolio for Accessing Global Engineering Information in User-Centered Environments, a research project that is currently being investigated by Ercegovac and sponsored by the Engineering Information Foundation. The following three features are explicated in the project.

1. PREFACE metaphor. Physical library is self-describing in many important ways. It is confined with physical boundaries, and typically contains charts, signage, reference librarians, a catalog, an information (smart) kiosk, and a myriad of discovery tools each designed for different purposes and user needs. Today's digital libraries lack this layer of information that shows content, context, structure, capabilities, and limits of collections. What is needed is a ``preface'' describing the scope, domain, and how collections and objects relate to other collections and objects.
2. USER metaphor. So far metadata standards have directed their attention to describing content analysis rather than user characteristics. We need attributes containing time- generated profile of users along with their capabilities, preferences, and path models which focus on usage histories rather than content analysis alone.
3. INSTRUCTIONAL metaphor. People continue to have numerous difficulties even with graphical user interfaces and other advanced capabilities; many powerful tools go little or rarely used. In other words, it is not only important that tools exist; as important is the deployment of effective literacy guides.

Seamless metadata

People, by definition, are processors of multimedia inputs. We are engaged in processing audio, graphical, animation, textual and numerical inputs. However, conceptually different metadata standards have been created independently to describe relatively homogeneous data sets within different disciplinary traditions. For example, the library community designed the Anglo-American Cataloging Rules / Machine Readable Cataloging (AACR2/USMARC) as a metadata standard that was initially and predominantly used to describe books; while the standard was later extended to include non-book formats such as rare books and manuscripts, cartographic materials, graphical objects, and sound recordings, many non-book formats were represented with book- related attributes. Similarly, other traditions have developed their own metadata (e.g., Encoded Archival Description (EAD), Federal Geographic Data Committee (FGDC), Text Encoding Initiative (TEI), and Visual Resources Association (VRA). Only recently have we seen the attempt to, for example, mesh FGDC Content Standard for Spatial Metadata with the AACR2/MARC Format. The Dublin Core with its guiding principles represents a new direction that accommodates multiple data types into a single underlying super-structure model. What we need next is to incorporate user profiles into user- centered metadata standards. One of the early attempts in this direction is the Learning Portfolio project which contains multiple layers of learning tools that reflect learning stages of different user groups in different engineering disciplines. Some of the research questions pertain to vocabulary control (e.g., semantic clusters of, for example, the author concept, which may be known as a creator, responsible party, provenance, originator, etc., in different metadata); ability to locate resources throughout their lives; deciding what should be described, who would describe, and to what extent, to mention just a few issues before us.