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Editorial changes to terms in DCMES

Title: Editorial changes to terms in the Dublin Core
              Metadata Element Set (DCMES)
Identifier: http://dublincore.org/usage/decisions/2006/2006-03.dcmes-changes.shtml
Date: 2006-12-18

  1. About this decision text

In 2006, the DCMI Usage Board undertook an editorial revision of terms in the Dublin Core Metadata Element Set (DCMES) in order to clarify intended semantics and bring the wording of their definitions and usage comments into line with the language of the DCMI Abstract Model [DCAM].

An initial set of changes was posted for Public Comment from 28 August to 25 September 2006 [PUBLIC-COMMENT]. The comments received were discussed at a face-to-face Usage Board meeting in Manzanillo, Mexico, on 30 September 2006 [MANZANILLO]. This document reflects decisions taken with respect to the Public Comment document in Manzanillo [MANZANILLO-DECISIONS] and on a subsequence teleconference of 27 October [TELECON-DECISIONS]. A separate document details the response to comments made [RESPONSE].

The wordings recorded here are reflected in revised versions of the documents "DCMI Metadata Terms" [DCTERMS], "Dublin Core Metadata Element Set, Version 1.1: Reference Description" [DCMES], and "DCMI Metadata Terms: A complete historical record" [DCTERMS-HISTORY].

All of the changes recorded here were evaluated by the DCMI Usage Board in light of the DCMI Namespace Policy [NAMESPACE]. The namespace policy says that DCMI terms are identified using Uniform Resource Identifiers (URIs). In accordance with the principle that distinct URIs should be assigned to distinct resources, the policy sets limits on the range of editorial changes that may allowably be made to the official labels, definitions, and usage comments associated with DCMI terms. By policy, any changes of meaning judged "likely to have a substantial impact on either machine processing of DCMI terms or the functional semantics of the terms" must trigger the creation of a new, distinct term with a new, distinct URI.

In the opinion of the Usage Board, the changes described in this document are unlikely to have a substantial impact on either machine processing of DCMI terms or the functional semantics of the terms -- i.e., they fall within the allowable range of editorial change. The changes constitute clarifications of term semantics in light of improved theoretical understanding, user feedback, and implementation experience. They provide the final twist of the lens that brings intended meanings more sharply into focus.

  1. Decision texts

2.1. URI: http://purl.org/dc/elements/1.1/title Label: Title Definition: A name given to the resource. Comment: Typically, a Title will be a name by which the resource is formally known.

2.2. URI: http://purl.org/dc/elements/1.1/creator Label: Creator Definition: An entity primarily responsible for making the resource. Comment: Examples of a Creator include a person, an organization, or a service. Typically, the name of a Creator should be used to indicate the entity.

2.3. URI: http://purl.org/dc/elements/1.1/subject Label: Subject Definition: The topic of the resource. Comment: Typically, the topic will be represented using keywords, key phrases, or classification codes. Recommended best practice is to use a controlled vocabulary. To describe the spatial or temporal topic of the resource, use the Coverage element.

2.4. URI: http://purl.org/dc/elements/1.1/description Label: Description Definition: An account of the resource. Comment: Description may include but is not limited to: an abstract, a table of contents, a graphical representation, or a free-text account of the resource.

2.5. URI: http://purl.org/dc/elements/1.1/publisher Label: Publisher Definition: An entity responsible for making the resource available. Comment: Examples of a Publisher include a person, an organization, or a service. Typically, the name of a Publisher should be used to indicate the entity.

2.6. URI: http://purl.org/dc/elements/1.1/contributor Label: Contributor Definition: An entity responsible for making contributions to the resource. Comment: Examples of a Contributor include a person, an organization, or a service. Typically, the name of a Contributor should be used to indicate the entity.

2.7. URI: http://purl.org/dc/elements/1.1/date Label: Date Definition: A point or period of time associated with an event in the lifecycle of the resource. Comment: Date may be used to express temporal information at any level of granularity. Recommended best practice is to use an encoding scheme, such as the W3CDTF profile of ISO 8601 [W3CDTF].

2.8. URI: http://purl.org/dc/elements/1.1/type Label: Type Definition: The nature or genre of the resource. Comment: Recommended best practice is to use a controlled vocabulary such as the DCMI Type Vocabulary [DCMITYPE]. To describe the file format, physical medium, or dimensions of the resource, use the Format element.

2.9. URI: http://purl.org/dc/elements/1.1/format Label: Format Definition: The file format, physical medium, or dimensions of the resource. Comment: Examples of dimensions include size and duration. Recommended best practice is to use a controlled vocabulary such as the list of Internet Media Types [MIME].

2.10. URI: http://purl.org/dc/elements/1.1/identifier Label: Identifier Definition: An unambiguous reference to the resource within a given context. Comment: Recommended best practice is to identify the resource by means of a string conforming to a formal identification system.

2.11. URI: http://purl.org/dc/elements/1.1/source Label: Source Definition: The resource from which the described resource is derived. Comment: The described resource may be derived from the related resource in whole or in part. Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.

2.12. URI: http://purl.org/dc/elements/1.1/language Label: Language Definition: A language of the resource. Comment: Recommended best practice is to use a controlled vocabulary such as RFC 3066 [RFC3066].

2.13. URI: http://purl.org/dc/elements/1.1/relation Label: Relation Definition: A related resource. Comment: Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.

2.14. URI: http://purl.org/dc/elements/1.1/coverage Label: Coverage Definition: The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant. Comment: Spatial topic may be a named place or a location specified by its geographic coordinates. Temporal period may be a named period, date, or date range. A jurisdiction may be a named administrative entity or a geographic place to which the resource applies. Recommended best practice is to use a controlled vocabulary such as the Thesaurus of Geographic Names [TGN]. Where appropriate, named places or time periods can be used in preference to numeric identifiers such as sets of coordinates or date ranges.

2.15. URI: http://purl.org/dc/elements/1.1/rights Label: Rights Definition: Information about rights held in and over the resource. Comment: Typically, rights information includes a statement about various property rights associated with the resource, including intellectual property rights.

  1. General categories of change

3.1. Replacement of the phrase "the content of the resource" (or "intellectual content of the resource") with "the resource".

 Implementation experience has shown the semantic
 distinction between a resource and the "content of"
 a resource to be a source of confusion.

 According to the DCMI Abstract Model, a DCMI metadata
 description "describes one, and only one, resource"
 [DCAM]. In the DCMI context, this principle dates
 back to 1997, when it was known as the "one-to-one
 principle". When the one-to-one principle is
 correctly followed, the semantic restriction to
 "the content of" a resource is in effect redundant.

 Moreover, Dublin Core elements are used to describe
 things other than document-like resources -- things such
 as physical objects and abstract concepts. For example,
 a stuffed animal has a Creator (perhaps a taxidermist, 
 or an artist) but that person is not specifically the 
 creator of "the content of" the stuffed animal. In light 
 of current usage, the meaning of the original distinction 
 between a resource and its content is no longer clear.

 In the opinion of the Usage Board, dropping the words
 "the content of" from definitions affirms the semantics of
 these terms as they have been understood in practice and
 with no significant practical impact on implementation.

 This change is relevant to the definitions of Contributor,
 Creator, Coverage, Description, Subject, Type, and
 Language.

3.2. Replacement of the phrase "a reference to a resource" with "a resource".

 In metadata, a related resource can be "referred to" only
 by means of a "reference", whether that reference is a
 text description or a formal identifier. The extra words
 are therefore redundant. The recommendation that formal
 identifiers be used is retained in the usage comments.

 This change is relevant to the definitions of Source
 and Relation and to the comment for Description.

3.3. Replacement of phrases such as "use a value from an encoding scheme" and "select a value from a controlled vocabulary" with "use a controlled vocabulary".

 The wording "use a controlled vocabulary" is more
 concise. The term "controlled vocabulary" is intentionally
 broad.

 This change is relevant to the comments for Coverage,
 Format, Subject, and Type.

3.4. Deletion of word "Resource" from the labels "Resource Type" and "Resource Identifier".

 In the DCMI context, the terms Type and Identifier are
 the only two to have used the qualifier "resource" in
 their labels. For example, Title is not called "Resource
 Title" and Date not "Resource Date". This inconsistency
 has been corrected by dropping the unnecessary reference
 to "resource" in the labels of Type and Identifier.
 This change also brings the labels of the elements ("Type"
 and "Identifier") in line with their names ("type" and
 "identifier").

3.5. Replacement of the phrase "a string or number conforming to a formal identification system" with "a string conforming to a formal identification system".

 A number is also a string, so the words "or number"
 are redundant.

 This change is relevant to the comments for Identifier,
 Relation, and Source.
  1. Changes with respect to DCMES of June 2005 [DCMITERMS], term by term

4.1. Title

  No changes.

4.2. Creator

  -- In definition, replaces "content of the resource"
     with "resource" [see Section 3.1]

4.3. Subject

  -- Changes label from "Subject and Keywords" to
     "Subject". It continues to be acknowledged in the
     comment that a subject may be expressed with keywords.
     This change also brings the label of the element 
     ("Subject") in line with its name ("subject").

  -- In the comment, advises that the Coverage element
     be used to describe the spatial or temporal topic
     of the resource.

  -- In definition, replaces "content of the resource"
     with "resource" [see Section 3.1]

  -- In comment, replaces "use a value from an encoding
     scheme" with "use a controlled vocabulary" [see
     Section 3.3]

  -- In comment, "expressed as" reworded as "represented using".

4.4. Description

  -- In definition, replaces "content of the resource" 
     with "resource" [see Section 3.1]

  -- In comment, replaces "a reference to a resource" with "resource" 
     [see Section 3.2]

4.5. Publisher

  -- In definition, addition of missing full stop.

4.6. Contributor

  -- In definition, replaces "content of the resource"
     with "resource" [see Section 3.1]

4.7. Date

  -- As with Language [see Section 4.12], the reference to a 
     specific encoding scheme in the comment is changed from
     "recommended best practice" to the status of an example.
     Hence: "Recommended best practice is to use an encoding
     scheme, such as the W3CDTF profile of ISO 8601 [W3CDTF]".

  -- The intended scope of the Date element has been the object
     of much discussion in the DCMI community. In practice,
     Date has long been interpreted to include the notion of a
     date range. The release in July 2000 of a first set of
     "Dublin Core qualifiers" -- which included Available,
     defined as referring to a "date (often a range)" --
     consolidated this interpretation. The Usage Board has
     now brought the definition of Date into line with this
     long-standing practical interpretation by explicitly
     allowing date ranges. Hence: "A point or period of
     time associated with an event in the lifecycle of the
     resource."

4.8. Type

  -- In definition, replaces "content of the resource"
     with "resource" [see Section 3.1]

  -- In comment, replaces the phrase "select a value from
     a controlled vocabulary" with "use a controlled vocabulary"
     [see Section 3.3]

  -- In label, changes "Resource Type" to "Type" [see Section 3.4]

4.9. Format

  -- The definition of Format as "The physical or
     digital manifestation of the resource" has been a
     source of confusion. For example, it is sometimes
     misinterpreted as referring to a related resource
     that is a "manifestation" in the sense of Functional
     Requirements for Bibliographic Records (FRBR).

  -- The new wording moves words from the original comment
     for Format into the definition in order to describe
     the intended meaning more concretely.

  -- In comment, replaces "select a value from an encoding
     scheme" with "use a controlled vocabulary" [see
     Section 3.3]

4.10. Identifier

  -- Definition unchanged.

  -- In comment, replaces "a string or number conforming
     to a formal identification system" with "a string
     conforming to a formal identification system"
     [see Section 3.5]

  -- In label, changed "Resource Identifier" to
     "Identifier" [see Section 3.4]

  -- In comment, deletes references to specific
     identification systems

4.11. Source

  -- In the definition, changes "present resource" to
     "described resource", both more precise and consistent
     with the DCMI Abstract Model

  -- In definition, replaces "a reference to a resource" with "resource" 
     [see Section 3.2]

  -- In comment, replaces "a string or number conforming to a formal 
     identification system" with "a string conforming to a formal 
     identification system" [see Section 3.5]

4.12. Language

  -- Six of the fifteen elements of DCMES -- Type, Format,
     Coverage, Subject, Language, and Date -- are
     recommended to be used with encoding schemes.
     Only in the cases of Language and Date, however,
     did the comments prescribe specific encoding schemes.
     In current DCMI practice, the prescription of encoding
     schemes (i.e., of "controlled vocabularies" - see
     Section 3.3) is seen as being more properly the role
     of an application profile, not of a term declaration.
     The Usage Board therefore amended the comment to
     reflect this, retaining a reference to one controlled
     vocabulary as an example.

  -- In definition, replaces "content of the resource" 
     with "resource" [see Section 3.1]

  -- In comment, replaces "use a value from an encoding
     scheme" with "use a controlled vocabulary" [see
     Section 3.3]

4.13. Relation

  -- In definition, replaces "a reference to a resource"
     with "resource" [see Section 3.2]

  -- In comment, replaces "a string or number conforming to
     a formal identification system" with "a string conforming
     to a formal identification system" [see Section 3.5]

4.14. Coverage

  The scope and purpose of Coverage has been a topic
  of much discussion and interpretation. The wordings
  proposed by the Usage Board address several issues:

  -- Use of the word "extent" in the definition.

     The use of "extent" in Coverage has caused confusion
     with respect to Format (the comment of which refers to
     "dimensions" such as "size" and "duration") and to
     the term Extent -- a refinement of Format defined as
     "The size or duration of the resource".

     The new definition replaces the ambiguous phrase
     "extent or scope of the content of the resource"
     with the phrase "spatial or temporal topic of the
     resource".

  -- Reference in the comment to "jurisdiction".

     The notion of "jurisdiction" entered into the scope of
     Coverage at an early date as part of the comment and
     has informed a significant number of implementations.
     The Usage Board has made this meaning explicit by
     referring to "jurisdiction" in the definition itself.

 -- In definition, replaces "content of the resource"
    with "resource" [see Section 3.1]

 -- In comment, replaces the phrase "select a value from
    a controlled vocabulary" with "use a controlled
    vocabulary" [see Section 3.3]

4.15. Rights

  The definition remains unchanged as "Information about
  rights held in and over the resource". However, several
  long-recognized problems have been corrected as follows:

  -- The label has been changed from "Rights Management"
     to "Rights". The reference to "management" had more
     to do with possible uses of the element than with
     the substance of the element itself. This change
     also brings the label of the element ("Rights") into
     line with its name ("rights").

  -- The comment previously referred both to a "statement"
     and to a reference to a "service" that provides
     such a statement. The Usage Board sees this as an
     implementation issue not appropriately addressed in a 
     usage comment.

 -- The qualification that "no assumptions may be made"
    if the element is absent was removed from the comment.
    The point is inappropriate because it implies that 
    the element can only be used (or not) as part of a 
    fixed element set.

REFERENCES

[DC-GENERAL] http://www.jiscmail.ac.uk/lists/dc-general.html [DCAM] http://dublincore.org/documents/abstract-model/ [DCMES] http://dublincore.org/documents/dces/ [DCMITERMS] http://dublincore.org/documents/2005/06/13/dcmi-terms/ [DCTERMS-HISTORY] http://dublincore.org/usage/terms/history/ [DCTERMS] http://dublincore.org/documents/dcmi-terms/ [MANZANILLO-DECISIONS] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0611&L=dc-usage&P=1110 [MANZANILLO] http://dublincore.org/usage/meetings/2006/09/manzanillo/dcmes-changes/html/ [NAMESPACE] http://dublincore.org/documents/dcmi-namespace/ [PUBLIC-COMMENT] http://dublincore.org/usage/public-comment/2006/08/dcmes-changes/ [RESPONSE] http://dublincore.org/usage/decisions/2006/2006-03.response-to-comments.shtml [TELECON-DECISIONS] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0611&L=dc-usage&P=1219

Errata 2006-12-21: corrected "organisation" to "organization"