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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.
2. 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.
3. 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.
4. 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"