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(1) References to the standard "ISO 11179" should designate
"ISO/IEC 11179".
(2) The stated intention in DC 1.1 is to distinguish between
concepts and representations. To be used effectively for its
purpose of cross-domain searching, and to allow inheritance,
it is crucial for DC to have data element concepts. Yet, it is
also important to have one or more data element representations
for each DC element. The recommended approach for DC 1.1 is to
express a data element concept for each DC element, and to
annotate the representations. Each of the DC 1.1 entries should
have a single Concept Definition and one or more "Representation
Classes" (e.g., name, text, code, date, ...).
(3) The definition given for each DC 1.1 entry should be labeled
as "Concept Definition", and each Concept Definition should
express a single data element concept. Most of the DC elements
are currently compounds of multiple data elements, either because
they incorporate attributes (e.g., scheme, format, etc.) or
because they permit qualification to form sub-elements not fully
contained within the parent element. It is necessary that there
be a concept definition within DC 1.1 for each of the "unadorned"
data element concepts, exclusive of any attributes or qualified
sub-elements. (In XML parlance, DC 1.1 elements should refer to
the contents of the element container but not to any attributes
of the element.)
(4) Once each DC 1.1 element includes a Concept Definition,
it will not be necessary to have a separate data element
definition for each representation, because a data element
definition can be readily derived by pre-pending "The
[representation class] of" to the concept definition.
For example, the concept "Creator" is defined as: "An entity
primarily responsible for making the content of the resource".
Given that the Representation Class for "Creator" is "name",
the data element definition would be: "The name of an entity
primarily responsible for making the content of the resource".
This rule for deriving a data element definition from the
concept definition derivation rule should be prominently
accessible to users of the DC.
(5) Each of the 15 DC 1.1 entries should have a separate
attribute for its "Representation Class" (equivalent to
"Form of Representation" discussed in ISO/IEC 11179-3,
clause 6.4.2).
(6) Each of the 15 DC 1.1 entries should include a separate
attribute for "Permissible Data Element Values" (specified
by ISO/IEC 11179-3, clause 6.4.7). The "Comment" included with
some of the DC elements contains guidance on permissible data
element values (e.g., "controlled vocabulary", "classification
scheme", "Dublin Core Types", "MIME", "ISBN", etc.) This
guidance should be moved to "Permissible Data Element Values"
(specific cases are described below).
(7) It is stated in DC 1.1 that the elements describe
"resources". The term "resource" is confusing since it is
very broad and is commonly applied to real-world entities
such as "human resources" and "water resources". While there
are ontological systems targeted primarily at real-world
entities, the "universe of discourse" for Dublin Core is
focused on the information aspects of resources. Accordingly,
the root concept should be "information resource".
(8) The DC 1.1 definitions should be consistent in using the
indefinite article ("a" or "an") versus the definite article
("the"). For concept definitions, the indefinite article should
be used, or the article can be dropped when possible.
(9) Eight of the DC 1.1 elements (Title, Publisher, Date, Format,
Resource Identifier, Source, Relation, and Rights) refer to the
"resource" irrespective of the "content", while the other DC
elements specifically refer to the "content of the resource".
There ought to be some description of the significance of the
distinction being made. The approach used in the Basic Semantic
Registry is to regard the content of the information resource as
the root concept. There is a secondary concept, "information
resource product", that defines an expression of the content in
specific products (including works, services, artifacts, type
specimens, etc.).
(10) DC 1.1 elements Creator, Contributor, and Publisher use the
term "entity" in their definitions. The dictionary defines entity
as a thing that has existence (not a very distinctive definition
and quite similar to the definition of "resource"). To clearly
evoke the sense of entities such as persons and corporations that
can act, the term "entity" should be replaced with "agent" or
"party".
(11) DC 1.1 element "Title", Definition:
Because "name" refers to a Representation Class, the current
DC 1.1 definition sounds like a data element definition rather
than a concept definition. A recommended Concept Definition
independent of Representation Class would be "Designation of
the information resource".
(12) DC 1.1 element "Title", Representation Class:
The recommended Representation Class is "name". (Per
ISO 1087-1, a "name" is "a designation of an individual
concept by a linguistic expression".)
(13) DC 1.1 element "Creator", Definition:
The term "entity" is not distinctive and should be replaced.
(14) DC 1.1 element "Creator", Representation Class:
The recommended Representation Class is "name".
(15) DC 1.1 element "Subject and Keywords", Definition:
In common use, "keywords" are often various terms used for
retrieval, but they are not necessarily descriptive of the
"topic". For example, "Cleveland" can be a retrieval keyword
for a Web page on a restaurant in Cleveland even though the
restaurant is not "about" Cleveland. If this concept is not
to be constrained to subject terms only, the word
"characteristic" is recommended rather than "topic".
(16) DC 1.1 element "Subject and Keywords", Comment:
The Comment should be clear that the element is exclusive
of any designation for controlled vocabularies or formal
classification schemes.
(17) DC 1.1 element "Subject and Keywords", Representation Class:
Because the concept defines a container having multiple keywords
or phrases, the Representation Class would be "group". To be
usefully applied, there is an implication that there exists a
separate concept defined to only include one keyword or phrase,
which concept would be inherited into this group definition.
(Otherwise, the group components are merely undifferentiated
character strings with no way to distinguish words from phrases,
for example.)
(18) DC 1.1 element "Subject and Keywords", Permissible Data
Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to select a value from
a controlled vocabulary or formal classification scheme."
(19) DC 1.1 element "Description", Definition:
The word "account" in the definition has different connotations
than "description". A recommended definition is: "A description
of the content of the information resource."
(20) DC 1.1 element "Description", Representation Class:
The recommended Representation Class is "text".
(21) DC 1.1 element "Contributor", Definition:
The term "entity" is not distinctive and should be replaced.
(22) DC 1.1 element "Publisher", Definition:
The phrase "making the resource available" in the definition
is not commonly understood as equivalent to "publishing". If
these are meant to be equivalent, the definition should say
"responsible for publishing the information resource".
(23) DC 1.1 element "Publisher", Representation Class:
The recommended Representation Class is "name".
(24) DC 1.1 element "Contributor", Definition:
The term "entity" is not distinctive and should be replaced.
(25) DC 1.1 element "Contributor", Definition:
The phrase "responsible for" in the definition is unnecessary
and could cause confusion.
(26) DC 1.1 element "Contributor", Representation Class:
The recommended Representation Class is "name".
(27) DC 1.1 element "Date", Definition:
The term "date" is used in ISO/IEC 11179 as a Representation
Class, so should not be in the Concept Definition. However,
it is necessary to convey the sense of a time point of
non-specific dimension. The recommended Concept Definition is:
"A point in time of an event relevant to the information
resource".
(28) DC 1.1 element "Date", Comment:
The Comment should make clear if the concept allows both
structured and unstructured representations and perhaps give
examples of how those might be distinguished using attributes
or other mechanisms.
(29) DC 1.1 element "Date", Comment:
ISO 8601 does not support "profiles". While it is possible to
constrain representations to a subset of ISO 8601, processors
dealing with ISO 8601 would be expected to handle any validly
formatted ISO 8601 date/time. There is an ANSI standard, X3.30,
in which only YYYYMMDD is valid.
(30) DC 1.1 element "Date", Representation Class:
The recommended Representation Class is "date", following the
guidance given in ISO/IEC TR 15452, Specification of data value
domains, associated with ISO/IEC 11179. If it is desired that
the concept also be applied to unstructured text for dates
(e.g. "Renaissance"), a second Representation Class would be
"name".
(31) DC 1.1 element "Date", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice for encoding the date value
is defined in a profile of ISO 8601 [W3CDTF] and follows the
YYYY-MM-DD format."
(32) DC 1.1 element "Resource Type", Comment:
The Comment should be clear that the element is exclusive of
the designation for a controlled vocabulary.
(33) DC 1.1 element "Resource Type", Representation Class:
The recommended Representation Class is "name".
(34) DC 1.1 element "Resource Type", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to select a value from
a controlled vocabulary (for example, the working draft list of
Dublin Core Types [DCT1])."
(35) DC 1.1 element "Format", Comment:
The Comment should be clear that the element is exclusive of
the designation for a controlled vocabulary.
(36) DC 1.1 element "Format", Representation Class:
The recommended Representation Class is "name".
(37) DC 1.1 element "Format", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to select a value from
a controlled vocabulary (for example, the list of Internet Media
Types [MIME] defining computer media formats)."
(38) DC 1.1 element "Resource Identifier", Comment:
The Comment should be clear that the element is exclusive of
the designation for a formal identification system.
(39) DC 1.1 element "Resource Identifier", Comment:
ISO/IEC 11179-6 may also be cited in the Comment as a source
for examples of formal identification systems.
(40) DC 1.1 element "Resource Identifier", Representation Class:
The recommended Representation Class is "name". /ISO
(41) DC 1.1 element "Resource Identifier", Permissible Data
Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to identify the resource
by means of a string or number conforming to a formal
identification system. Example formal identification systems
include the Uniform Resource Identifier (URI) (including the
Uniform Resource Locator (URL)), the Digital Object Identifier
(DOI) and the International Standard Book Number (ISBN)."
(42) DC 1.1 element "Source", Comment:
The Comment should be clear that the element is exclusive of
the designation for a formal identification system.
(43) DC 1.1 element "Source", Comment:
In the Comment, add the phrase "including but not limited to
a Resource Identifier".
(44) DC 1.1 element "Source", Representation Class:
The recommended Representation Class is "name".
(45) DC 1.1 element "Source", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to reference the resource
by means of a string or number conforming to a formal
identification system."
(46) DC 1.1 element "Language", Definition:
This is the only use of the term "intellectual" as a modifier
for content. If the adjective is necessary, the distinction
should be defined since it is not commonly understood.
(47) DC 1.1 element "Language", Representation Class:
The recommended Representation Class is "code".
(48) DC 1.1 element "Language", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice for the values of the
Language element is defined by RFC 1766 [RFC1766] which includes
a two-letter Language Code (taken from the ISO 639 standard
[ISO639]), followed optionally, by a two-letter Country Code
(taken from the ISO 3166 standard [ISO3166]). For example,
"en" for English, "fr" for French, or "en-uk" for English
used in the United Kingdom."
(49) DC 1.1 element "Relation", Comment:
The Comment should be clear that the element is exclusive
of the designation for a formal identification system.
(50) DC 1.1 element "Relation", Comment:
In the Comment, add the phrase "including but not limited
to a Resource Identifier". /REMARK
(51) DC 1.1 element "Relation", Representation Class:
The recommended Representation Class is "name".
(52) DC 1.1 element "Relation", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Recommended best practice is to reference the
resource by means of a string or number conforming to a
formal identification system."
(53) DC 1.1 element "Coverage", Comment:
The Comment should be clear that the element is exclusive
of the designation for a controlled vocabulary.
(54) DC 1.1 element "Coverage", Definition:
"Extent" and "scope" are very similar in meaning and neither
evoke a sense of temporal extent. A recommended definition is:
"An extent or duration of the content of the information
resource".
(55) DC 1.1 element "Coverage", Representation Class:
The recommended Representation Class is "text".
(56) DC 1.1 element "Coverage", Permissible Data Values:
Move from the Comment to Permissible Data Values the guidance
given as "Coverage will typically include spatial location
(a place name or geographic co-ordinates), temporal period
(a period label, date, or date range) or jurisdiction (such
as a named administrative entity). Recommended best practice
is to select a value from a controlled vocabulary (for example,
the Thesaurus of Geographic Names [TGN])."
(57) DC 1.1 element "Rights Management", Name and Identifier:
The term "management" does not make sense in "Rights Management",
especially as the definition refers to "information" and the
comment refers to a "statement". The Name and Identifier should
be "Constraints".
(58) DC 1.1 element "Rights Management", Definition:
The meaning of the phrase "held in and over" is not clear
to a reader, though it does have the ring of legal jargon.
(59) DC 1.1 element "Rights Management", Definition:
It seems as though the definition is backwards--it is certainly
not meant to be a full statement of the rights of the legal
entities. Rather, one would expect to find statements by
owners and their agents granting or constraining the rights
of users to either access or use the information resource.
(Privacy considerations give rise to access constraints,
intellectual property considerations give rise to use
constraints, for example.)
(60) DC 1.1 element "Rights Management", Comment:
The last sentence of the Comment seems completely out of
place. Clearly the issue referenced is related to national
and international law. One could say, perhaps, that no rights
of access or use are granted in the absence of a granting
statement, though this may well not hold up in court. The
Internet convention seems to be that in the absence of a
constraints statement there are no constraints on access
or use.
(61) DC 1.1 element "Rights Management", Comment:
It is not clear whether the referenced rights are from the
perspective of the owner ("intellectual property rights")
or the rights of the user ("copyright").
(62) DC 1.1 element "Rights Management", Representation Class:
The recommended Representation Class is "text".
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Eliot Christian, US Geological Survey, 802 National Center, Reston VA 20192
echristi@usgs.gov Office 703-648-7245 FAX 703-648-7112 Home 703-476-6134
-- Anonymous, July 21, 1999