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DATE: May 25, 2023
REVISED:
NAME: Refinement of Accessibility Field 341 in the MARC 21 Bibliographic Format
SOURCE: Canadian Committee on Metadata Exchange (CCM)
SUMMARY: This paper suggests adjustments to the Field Definition and Scope of MARC Bibliographic field 341 (Accessibility Content) and to the description of 341 subfield $a (Content access mode).
KEYWORDS: Field 341 (BD); Accessibility content (BD); Subfield $a, in field 341 (BD); Content access mode (BD); Acessibility (BD)
RELATED: 2018-03; 2017-11; 2017-DP03
STATUS/COMMENTS:
05/25/23 – Made available to the MARC community for discussion.
06/28/23 – Results of MARC Advisory Committee discussion: MAC generally supported broadening the Field Definition and Scope. There was a split in choice of Option 1 and Option 2 in discussions. A straw poll indicated a slight preference for Option 2 over Option 1. For Option 2, MAC expressed concern about the last sentence, and suggested the precedent set out in MARC 21 field range 34X and the 382 field when recording controlled vocabularies. The paper will return as a proposal.
MARC Field 341 (Accessibility Content) was added to the MARC 21 Bibliographic Format in November 2018. In February 2022, the Network Development and MARC Standards Office (NDMSO) of the Library of Congress added sapdv (Schema.org Accessibility Properties for Discoverability Vocabulary) to its list of Accessibility Content Source Codes approved for use with MARC Field 341.
Implementation of the new source code in Field 341 has highlighted some unnecessary restrictions in the Field Definition and Scope. These restrictions impede full use of the new source code.
Field 341 is currently defined, in part, in the MARC 21 Bibliographic Format as follows:
FIELD DEFINITION AND SCOPE
Information about modes of access to the content of a resource, including its primary mode of access and alternative mode(s) of access.Each occurrence of the field requires one subfield $a to record the mode of access for which an alternative mode is provided and one or more $b-$e subfields identifying the type of alternative access. Values for subfields $b-$e should be taken from the same controlled vocabulary.
Multiple values from the same source vocabulary may be recorded in the same field in separate occurrences of subfields. Terms from different source vocabularies are recorded in separate occurrences of the field.
SUBFIELD CODES
$a - Content access mode
Mode required to access the content of the resource without using assistive features (one of textual, visual, auditory, or tactile).341 0#$aauditory
The current Field Definition and Scope for 341 restricts the use of the field to "alternative modes of access" to the primary mode of access to a resource. Rewording of the Field Definition and Scope to broaden its use to describe all accessibility features of a resource would greatly expand the type of resources this field could be used to describe. For example, display transformability or a navigable table of contents in electronic books are accessibility features and not alternative modes of access.
Additionally, the approval of the sapdv source code has highlighted some ambiguity in the use of subfield a. $a (Content access mode). The current Field Definition limits the content access modes to four options: textual, visual, auditory, tactile. Schema.org Accessibility Properties for Discoverability Vocabulary provides for 11 modes of access. In addition to the four provided for in the current definition, these are: chartOnVisual, chemOnVisual, colorDependent, diagramOnVisual, mathOnVisual, musicOnVisual, textOnVisual. With the exception of colorDependent, these additional modes of access specify types of content that are presented as images rather than as parseable text.
In order to accommodate this level of granularity related to visual content, this discussion paper presents two options to adjust the current definition of 341 subfield $a. Option 1 proposes additional text to clarify that the mode visual includes all types of content presented as images. Option 2 proposes that the Field Definition no longer prescribes the vocabulary for subfield $a, and instructs the cataloger to use the same source vocabulary cited in subfield $2 for all subfields in each occurrence of the field, including $a.
(Note: changes indicated by strikethroughs and bold text)
Revise the Field Definition and Scope for MARC Bibliographic field 341 (Accessbility Content) as follows:
FIELD DEFINITION AND SCOPE
Information about modes of access to the content of a resource, including its primary mode of access and
alternative mode(s) of accessaccessibility features.
Each occurrence of the field requires one subfield $a to record the mode of access for which analternative modeaccessibility feature is provided and one or more $b-$e subfields identifying the type ofalternative accessaccessibility features. Values for subfields $b-$e should be taken from the same controlled vocabulary.
Multiple values from the same source vocabulary may be recorded in the same field in separate occurrences of subfields. Terms from different source vocabularies are recorded in separate occurrences of the field.
OPTION 1:
Revise definition to explicitly group more granular types of image-based content under the visual mode of access.
$a - Content access mode
Mode required to access the content of the resource without using assistive features (one of textual, visual, auditory, and tactile). Take visual to include charts, chemical equations, diagrams, mathematical equations, music notation, and text presented as images rather than parseable text.
OPTION 2:
Revise to allow values from any vocabulary identified in $2 to be used in $a.
$a - Content access mode
Mode required to access the content of the resource without using assistive features(one for textual, visual, auditory, and tactile)(for example, textual, auditory, or visual mathematical equations). Use terms from the same vocabulary used to populate subfields $b-e.
Example 1: An ePub enhanced with accessibility features.341 0# $atextual$bprintPageNumbers$bstructuralNavigation$btableOfContents$btaggedPDF$2sapdv
Example 2: A DAISY audio disc with accessibility features.
341 0# $aauditory$dpageBreakMarkers$dpageNavigation$dstructuralNavigation$2sapdv
Example 3: An electronic version of a mathematics textbook with equations presented as images rather than as text, where textual descriptions of equations have been provided using MathML.Option 1: Using currently prescribed vocabulary for subfield $a:
341 0# $avisual$bdescribedMath$bMathML$2sapdv
Option 2: Using source vocabulary identified in subfield $2 for subfield $a:
341 0# $amathOnVisual$bdescribedMath$bMathML$2sapdv
The ContentAccessibility class/property has not been fully developed in BIBFRAME.
6.1. Has the case for revising the Field Definition and Scope for field 341 (Accessibility Content) been made?
6.2. Has the case for revising the description of 341 subfield $a (Content access mode) been made?
6.3. Of the two options presented for rewriting 341 subfield $a, which is preferable?
6.4. Is there anything else that should be considered?
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