For hundreds of years, librarians have wanted to exchange cataloguing information, but while it may not seem to be an especially arduous task, it has concealed many obstacles. Not only has it been difficult to actually get people to commit to exchanging their information: to go to the trouble of making that extra catalogue card and send it to the proper place or to export records; there were further problems concerning standards and quality: to ensure a single size of a catalogue card or a single computer format. Even once these issues are solved, the problems refuse to disappear, since issues of quality of content arise: what form of the corporate name should be chosen? Which title do I choose?
All of these problems are still with us today, not least because the traditional solutions have always required the acceptance of uniform standards, which means that some unfortunate people must change everything they do and accept someone elses standards. As a result, some institutions are forced to abandon their methods, thereby making the labour of years or decades obsolete, so that they can move confidently into the future.
Today, now that computer capabilities have reached a sufficiently high level, this no longer holds true. We believe that the AGRIS AP, although it does not currently solve all of the problems of information exchange, is a major step in the right direction. Anyone can exchange metadata or cataloguing information, and - best of all - no one needs to change a thing that they do. All they have to do is share in the correct way.
In this paper, we shall attempt to show how this has been achieved in the context of the AGRIS[1] information system[2].
Case Scenario
There are several reasons to exchange metadata information: from enhanced searching, to workflow issues, such as avoiding retyping information that has already been input once, or metadata harvesting for value added services. The reasons are many, but what are the problems in exchanging metadata information?
Lets look at a real example of metadata records to see exactly how they differ and what are the consequences of exchanging records. Figures 1 and 2 show two records that describe the same item. Figure 1 is in MARC21/AACR[3] and Figure 2 is in AGRIN3/AGRIS[4] format.
1.1. Different record structures and applications
The MARC21 record could have been created in many applications (Voyager, ISIS, Horizon, etc.), but it must be in ISO2709 record structure. The AGRIN record is created in CDS/ISIS but could be in Tag Text (a text file with a tag number and relevant value, separated by a carriage return), AGRIN2 (an old CDS/ISIS format) and AGRIN3 (a revised CDS/ISIS format, based on the ISO2709 structure. Many databases use relational database structures, completely bypassing ISO2709.
010 __ |a 2001023765 |
Figure 1. MARC21/AACR2 record
100: Welcomme, R.L.^b(comp.) |
Figure 2. AGRIN3/AGRIS Record
1.2. Different content designations for the same bibliographic concept
ISO2709 is not enough, but just the beginning of exchange; now we have the problem of different content designations. The MARC21 record is obviously in MARC21, but there are many other MARC formats in the world. Different content designators, where different codes are used to represent the same concept, inhibit interoperability. For example, the MARC21 record uses the 245 field for Title while AGRIN3 uses the 200 field. Another example, 650 in MARC21 and 800 in AGRIN3 represent the same concept (subject) but use different content designators.
New standards have placed new demands for interoperability, for example, the OpenURL[5] standard is not supported by many older content designations.
1.3. Different conceptual bibliographic metadata
The MARC21 record has some concepts that do not exist in the other record. One example is the concept of Main Entry, represented here by the author R.L. Welcomme, who is considered to be the primary author. The AGRIS record does not have the concept of Main Entry.
There are concepts from other standards that neither side completely fulfils: full compliancy with the OpenURL standard, new concepts from the Functional Requirements for Bibliographic Records[6] (FRBR).
1.4. Different cataloguing rules
There are many cataloguing rules in use in the world. The MARC21 format primarily uses the AACR2 cataloguing rules. The AGRIN3 format uses the rules according to the AGRIS Cataloguing guidelines. For example, the place of publication in the AGRIS cataloguing guidelines, is entered as City (Name of the Country) while in AACR2, the place of publication is transcribed as it is found on the resource and an additional place of publication is added into the record.
AGRIS: 401: Oxford (United Kingdom)
AACR2: 260__ |a Oxford; |a Malden, MA
1.5. Variant treatments for different formats (one record/multiple records)
When a similar item appears on the internet in a different format from the printed version, how is it handled: simply by adding the URL to the original record, or is an entirely new record created? In the AGRIN3/AGRIS record, the URL is merely added to the record, whereas in MARC21/AACR2, a new record would most probably be required.
1.6. Multilinguality
Some formats have a greater focus on multiple languages. The AGRIS record shown here has special fields for titles in each language. Therefore, an English title is coded differently from a Spanish title. This is absent in MARC21. There are several standards for encoding non-ASCII[7] character sets, such as Unicode[8].
1.7. Other Differences in Bibliographic Concepts and Granularity.
Different systems use their own choices of metadata elements which results in different levels of granularity. For example, in MARC21/AACR2, titles are encoded in the following way:
245 10 ^a Inland fisheries: ^b ecology and management
Where:
245 = Title statement
10 = Main entry/added entry indicator and filing indicator
^a Title proper
^b Other title information (or subtitle, separated by a space-colon-space)
In AGRIN3/AGRIS format (see Figure 2), this title is encoded as:
200 Inland fisheries: ecology and management
Where:
200= English language title
The above example shows that, depending on the catalogue, the same title of the resource may be added in either one or two different fields.
If the title were in French, it would be placed into a 202 field in AGRIN3/AGRIS record. In MARC21/AACR2, language of Title is irrelevant.
[1] AGRIS home page
http://www.fao.org/agris/ [2] AGRIS is the international information system for the agricultural sciences and technology, created by the Food and Agriculture Organization of the United Nations (FAO) in 1974. The main purpose of the AGRIS system is to facilitate information exchange and to bring together scientific and technical literature, especially non-conventional (grey) literature, dealing with all aspects of agriculture. [3] MARC Standards / Library of Congress. http://www.loc.gov/marc/. See also: Anglo-American Cataloguing Rules: 2002 Revision. American Library Association [4] AGRIS: guidelines for bibliographic description and input sheet preparation. Rome: Food and Agriculture Organization of the United Nations, Jan. 1998. Available from: ftp://ext-ftp.fao.org/GI/agris/pdf/guidelns/main.pdf [5] The OpenURL standard. http://www.niso.org/committees/committee_ax.html [6] Functional Requirements for Bibliographic Records. http://www.ifla.org/VII/s13/frbr/frbr.pdf [7] Non Ascii character set. [8] Unicode standard. http://www.unicode.org/ |