Thanks, Diane, for the history. It's always hard to understand without
the subtext of *how* things have come about.
I have no strong interest one way or the other about a solution. But I
am curious to know what usage of dc:coverage you prefer that would
return to the
"previous definition (or something new) that does not assume topicality,
> and perhaps even eschews that usage."
A few examples would probably make things clearest. I realize that you
gave examples in your post, but without the context it isn't possible to
know if these eschew the topical usage. (And, yes, I realize that there
will be a considerable grey area between topical and non-topical, and I
don't feel a need to disambiguate the whole world, just to see a few
clear cases, which, then, may be useful in the documentation.)
Thanks,
kc
On 2/25/12 12:00 PM, Diane Hillmann wrote:
> Folks:
>
> As I recall, the change in the definition of 'Coverage' to include
> topicality occurred while I was still on the UB, and I'd like to think I
> spoke against it (though I have no evidence for that, just memory,
> faulty at best). Tom, who probably has to hand all the minutes of those
> meetings might be able to pinpoint the time the decision was made, and
> maybe even the conversations around that change, since he wrote all the
> reports.
>
> That said, I agree with Gordon--the problem is also with the definition
> of Coverage, which says:
>
> 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 and spatial applicability may be a named place or
> a location specified by its geographic coordinates. Temporal topic 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.
>
> /
> /
>
> The Comment reinforces that definition, and its emphasis on topicality.
>
> Then I looked at 'Using Dublin Core'
> (http://dublincore.org/documents/usageguide/elements.shtml) which was
> last updated (by me, probably), in 2005, and it does not mention
> topicality at all:
>
> /Label: Coverage/
>
> /Element Description:/ The extent or scope of the content of the
> resource. 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 [Getty
> Thesaurus of Geographic Names, http://www.
> getty.edu/research/tools/vocabulary/tgn/
> <http://www.getty.edu/research/tools/vocabulary/tgn/>]). Where
> appropriate, named places or time periods should be used in preference
> to numeric identifiers such as sets of co-ordinates or date ranges.
>
> /Guidelines for content creation:/
>
> Whether this element is used for spatial or temporal information, care
> should be taken to provide consistent information that can be
> interpreted by human users, particularly in order to provide
> interoperability in situations where sophisticated geographic or
> time-specific searching is not supported. For most simple applications,
> place names or coverage dates might be most useful. For more complex
> applications, consideration should be given to using an encoding scheme
> that supports appropriate specification of information, such as DCMI
> Period <http://dublincore.org/documents/dcmi-period/>, DCMI Box
> <http://dublincore.org/documents/dcmi-box/> or DCMI Point.
> <http://dublincore.org/documents/dcmi-point/>
>
> /Examples:/
>
> Coverage="1995-1996"
> Coverage="Boston, MA"
> Coverage="17th century"
> Coverage="Upstate New York"
>
> My [faulty] memory suggests to me that the decision to include
> topicality in Coverage occurred around the time that we added domains
> and ranges, at which time I think we made some adjustments in
> definitions and comments.
>
> As Tom points out, the newer guidelines are likely to follow those
> changes closely (though for the life of me I can't find that document to
> quote from it).
>
> In any case, it seems to me that Gordon's logic is, as usual,
> impeccable, and we should consider specifically returning to the
> previous definition (or something new) that does not assume topicality,
> and perhaps even eschews that usage. I understand Karen's concerns
> completely (having taught this stuff since the dinosaurs walked the
> earth), and the questions I've answered over the years support her
> contention that people will not find this distinction easy to make, but
> I still think we should make it.
>
> Diane
>
> P.S. I've copied the Vocabulary Management Community list on this, under
> the assumption that they, too, will be interested in how this sausage is
> made.
>
>
> On Sat, Feb 25, 2012 at 2:07 PM, [log in to unmask]
> <mailto:[log in to unmask]> <[log in to unmask]
> <mailto:[log in to unmask]>> wrote:
>
> All
>
> My first point when discussing this with Tom was that there seems to
> be an
> inconsistency in the way dct:coverage is defined.
>
> dct:coverage and its sub-properties dct:spatial and dct:temporal include
> the subject aspect of their semantic in the definition. But this is
> not the
> case with any other dct attribute. For example, dct:language has
> definition
> "A language of the resource.", not "The language topic of the
> resource, or
> a language of the resource."
>
> This is not inconsistent, however, if we propose that the definition of
> dct:coverage is intended to be entirely subsumed by the definition of
> subject. That is, "the spatial applicability of the resource, or the
> jurisdiction under which the resource is relevant" is intended to
> refer to
> the topicality or "aboutness" of the resource; the spatial applicability
> and jurisdiction are assumed to be spatial topics of the resource.
>
> This appears to be supported by Karen's observation "if your map is
> coded
> with geographical coordinates for Berkeley, California, can you consider
> Berkeley, California the subject of the map? I think many people
> would." I
> expect similar arguments to be made for jurisdiction: that the
> geographical
> applicability of legislation is "about" that geographical entity.
>
> This implies:
>
> dct:coverage rdfs:subPropertyOf dct:subject .
>
> Then:
>
> dct:spatial rdfs:subPropertyOf dct:coverage .
> dct:temporal rdfs:subPropertyOf dct:coverage .
>
> entails:
>
> dct:spatial rdfs:subPropertyOf dct:subject .
> dct:temporal rdfs:subPropertyOf dct:subject .
>
> But the definitions of dct:spatial ("Spatial characteristics of the
> resource") and dct:temporal ("Temporal characteristics of the resource")
> are consistent with dct:language, and we don't generally want to say:
>
> dct:language rdfs:subProperty dct:subject .
>
> A document in a written language is not "about" that language, etc.
>
> This tends to suggest that the proposition that dct:coverage is a
> sub-property of dct:subject by virtue of its intended (but possibly
> unclear) definition is incorrect. That is, dct:coverage has a scope
> beyond
> "aboutness".
>
> This results in a problem for applications requiring an index of all
> subjects/topics "about" a resource. A subject index needs to cover the
> objects of triples using dct:coverage, dct:spatial, and dct:temporal, as
> well as dct:subject, and will thus include values which are not
> "about" the
> resource (i.e. false drops).
>
> And the same problem will arise when mapping elements from other
> bibliographic namespaces to dct.
>
> Cheers
>
> Gordon
>
>
--
Karen Coyle
[log in to unmask] http://kcoyle.net
ph: 1-510-540-7596
m: 1-510-435-8234
skype: kcoylenet
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