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DATE: December 14, 2023
REVISED:
NAME: Adding Subfield $1 to Fields 082 and 083 in the MARC 21 Formats
SOURCE: Dewey Editorial Team, OCLC
SUMMARY: This paper proposes adding subfield $1 (Real World Object URI) to fields 082 (Dewey Decimal Classification Number) and 083 (Additional Dewey Decimal Classification Number) in MARC 21 Authority, Bibliographic, and Community Information Formats.
KEYWORDS: DDC (AD, BD, CI); Dewey Decimal Classification Number (AD, BD, CI); Additional Dewey Decimal Classification Number (AD, BD); Field 082 (AD, BD, CI); Field 083 (AD, BD); Subfield $1, in Field 082 (AD, BD, CI); Subfield $1, in Field 083 (AD, BD); Real World Object URI (AD, BD, CI)
RELATED: 2023-DP09; 2021-04; 2020-FT03; 2020-FT02
STATUS/COMMENTS:
12/14/23 – Made available to the MARC community for discussion.
01/24/24 – Results of MARC Advisory Committee discussion: Approved, with an amendment to add subfield $0 (Authority record control number or standard number) to fields 082 and 083.
05/15/24 – Results of MARC Steering Group review - Agreed with the MAC decision.
This proposal follows Discussion Paper No. 2023-DP09, which advocated for the authorization of subfields $0 and $1 for Dewey Decimal Classification (DDC) fields: 082 in the Bibliographic, Authority, and Community Information formats; 083 in the Bibliographic and Authority formats.
Previously, DDC numbers have only had identifiers in the Classification-format 001 field; although this field can be viewed in WebDewey, it is only used internally within the DDC editorial system and in truth is tied to records rather than numbers. If a duplicate record is created for a DDC number, the records will have different 001 values.
Now, OCLC is launching Dewey as linked data as part of concepts modeling in WorldCat Entities, including defined URIs for individual DDC numbers. They are tied to the DDC numbers themselves and are intended to be actionable in linked data applications.
During discussion for the corresponding discussion paper, MAC expressed support for authorizing a subfield for DDC URIs, but there were mixed opinions on whether subfield $0 or subfield $1 would be the more appropriate usage. This also tied into a broader discussion about how those subfields are used in other contexts. We now propose the use of subfield $1 for these DDC MARC fields.
Since MAC agreed that there was value in authorizing a place for DDC URIs generally, this proposal will focus on the choice of subfield $1 over subfield $0, and answer some questions about implementation that came up in discussion of the previous discussion paper.
In the committee's more general discussion about subfields $0 and $1, a common theme was the need to minimize confusion for catalogers and to consistently model a given identifier type rather than mixing them across both subfields. At first glance, "Real World Object URI" seems like a strange choice for something like a DDC number, and this may have been what drove the committee to express a slight preference for subfield $0 here. But it is clear from definitions that concepts can also qualify as real-world objects in this context.
Committee discussion also noted that subfield $1 is better suited for linked data and Semantic Web applications. This has also driven OCLC to prefer subfield $1 for other URIs from WorldCat Entities, such as the existing person and title objects. Thus, we prefer to see DDC URIs recorded in subfield $1 as well.
There are two other matters from the discussion paper worth clarifying. The minutes indicate that only non-built DDC numbers would be in scope for the approximately 44,000 URIs that will initially be populated. In fact, what determines if a DDC number will have a URI is not whether or not it is a built number, but whether there is a record in Dewey web applications (e.g., the internal Editorial Support System [ESS], WebDewey). All non-built numbers are thus represented, but many built numbers are as well.
There is no official word in DDC's technical vocabulary for such a distinction, though we are starting to speak of "established" numbers. For example, 020 is a non-built number meaning library and information sciences. Through the normal number building process, a user can build 020.72 for library science research. This built number exists in the database, and thus will receive a URI, just as 020 will.
There are many, many valid DDC numbers that do not exist in the database, even if they may have been used in bibliographic records. All such numbers are built numbers (for example, 020.724, experimental research in library science). These numbers will not receive URIs, since there would be no corresponding information about them. However, new URIs will be created as new numbers are created—either because editors have authorized new non-built numbers, or because new built numbers have been entered into the system.
The committee also asked how the URI would relate to the whole of a field, versus just the DDC number itself in subfield $a. The URIs will correspond directly to the DDC number in subfield $a. They will be language independent.
Keeping in mind that OCLC does not plan to designate future editions, the URIs are best suited to the full current edition (i.e., 23). So long as a number has a URI, it could also be given in a field for the same DDC number in an abridged edition, or a previous edition. However, the meaning of a number can change between editions or in full versus abridged editions, and Dewey linked data will not be optimized for these historical usages.
The identifiers correspond to the DDC classes (or numbers) themselves. We do not plan to separately model Abridged DDC or previous editions. Since most numbers will have similar, sometimes even identical meanings in standard DDC as in abridgments or previous editions, catalogers may choose to use URIs even if they are not cataloging in standard DDC.
In field 082 (Dewey Decimal Classification Number) of the MARC 21 Bibliographic, Authority, and Community Information Formats, define the following subfield:
$1 - Real World Object URI (R)
See description of this subfield in Appendix A: Control Subfields.
In field 083 (Additional Dewey Decimal Classification Number) of the MARC 21 Bibliographic and Authority Formats, define the following subfield:
$1 - Real World Object URI (R)
See description of this subfield in Appendix A: Control Subfields.
Note: Currently, the URIs in the examples below are not actionable.
082 04 $a 891.6611 $1 https://id.oclc.org/worldcat/ddc/E3Vf9jhKTRtckdM8Br6J9bVdQ4
245 04 $a The burning tree : $b poems from the first thousand years of Welsh verse / $c selected and translated by Gwyn Williams.082 04 $a 363.37/7 $2 23 $1 https://id.oclc.org/worldcat/ddc/E3kkJqXYPRx7Xtb86HHqfJ8Pmg
100 1# $a Keane, Robert E., $e author.
245 10 $a Wildland fuel fundamentals and applications / $c Robert E. Keane.083 0# $a 968.87/02 $2 23/eng/20190402 $1 https://id.oclc.org/worldcat/ddc/E3HcW4YqmmxX8kYYkGFxKJ7VVM
082 04 $a 621.952 $2 23/eng/20230428 $1 https://id.oclc.org/worldcat/ddc/E3TvVHPKtMTK6d3HthHqXGT9Dq
150 ## $a Boring machinery082 04 $a 205 $2 23/eng/20230428 $1 https://id.oclc.org/worldcat/ddc/E48mJy8rrqx4VXWk38qDfdTjHf
150 ## $a Religious ethics083 00 $a 362.29/6 $2 23/eng/20190402 $1 https://id.oclc.org/worldcat/ddc/E3xRYvx99JwFqb4ggqMTGYxDqq
Adding subfield $1 could reduce the data loss in BIBFRAME to MARC conversion.
6.1. In field 082 (Dewey Decimal Classification Number) of the MARC 21 Bibliographic, Authority, and Community Information Formats, define subfield $1 (Real World Object URI).
6.2. In field 083 (Additional Dewey Decimal Classification Number) of the MARC 21 Bibliographic and Authority Formats, define subfield $1 (Real World Object URI).
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