Re: The meaning of Subject (and Coverage)
On 2/24/12 6:38 PM, Thomas Baker wrote: To be clear, the definition of dc:subject would remain unchanged: The topic of the resource. No definitions would change. The change I am proposing is that the usage guideline -- that Coverage be used instead of Subject to describe the spatial or temporal topic of the resource -- be dropped. This does not mean that anyone would have to change what they are doing -- e.g., to start using Subject for describe spatial or temporal topics instead of Coverage. However, it is not incorrect to use Subject with a spatial or temporal topic, and removing the usage guideline would remove any ambiguity in this regard. But aren't the guidelines guidelines not rules? The question is not what is or isn't in the guidelines, but what we think is the best practice. Note that the *definition* of dc:coverage includes spatial and temporal *topics*. Are you saying that you wish for there to be two options for spatial and temporal topics? I think that removing the usage guideline means the answer to that is yes. So I ask: is that a good idea? I also think that because the definition of dc:coverage explicitly states spatial and temporal topics, without some explanation there is increased ambiguity when the guideline is removed. kc Tom -- Karen Coyle kco...@kcoyle.net http://kcoyle.net ph: 1-510-540-7596 m: 1-510-435-8234 skype: kcoylenet
Re: The meaning of Subject (and Coverage)
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 On 25 February 2012 at 14:15 Karen Coyle kco...@kcoyle.net wrote: On 2/24/12 6:38 PM, Thomas Baker wrote: To be clear, the definition of dc:subject would remain unchanged: The topic of the resource. No definitions would change. The change I am proposing is that the usage guideline -- that Coverage be used instead of Subject to describe the spatial or temporal topic of the resource -- be dropped. This does not mean that anyone would have to change what they are doing -- e.g., to start using Subject for describe spatial or temporal topics instead of Coverage. However, it is not incorrect to use Subject with a spatial or temporal topic, and removing the usage guideline would remove any ambiguity in this regard. But aren't the guidelines guidelines not rules? The question is not what is or isn't in the guidelines, but what we think is the best practice. Note that the *definition* of dc:coverage includes spatial and temporal *topics*. Are you saying that you wish for there to be two options for spatial and temporal topics? I think that removing the usage guideline means the answer to that is yes. So I ask: is that a good idea? I also think that because the definition of dc:coverage explicitly states spatial and temporal topics, without some explanation there is increased ambiguity when the guideline is removed. kc Tom -- Karen Coyle kco...@kcoyle.net http://kcoyle.net ph: 1-510-540-7596 m: 1-510-435-8234 skype: kcoylenet
Re: The meaning of Subject (and Coverage)
Gordon, this now makes sense, thanks. I agree that it makes sense for all subjects to be under subject -- it also makes sense to me to have subject types as sub-properties of dc:subject. How far to go down that road is another question. I'm still confused, though, about the desired scope of dc:coverage. 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. I agree that it goes beyond aboutness, but the question is: is the non-topical aspect of coverage useful? Should the two uses (topical vs. 'spatial applicability') be split between dc:subject and dc:coverage? (I also wonder if it makes sense to put spatial and temporal together.) That said, we seem to be discussing some fundamental changes to DC terms, and I'm not sure that's practical. I can understand why one proposed solution was to remove the guidance statement from dc:subject, because that doesn't significantly change DC terms. But the issue seems to be that dc:coverage is encroaching on dc:subject in an odd way, and it is the definition of dc:coverage that would need to be changed, as well as its relationship to dc:subject. This is then a significant change and clearly would need serious consideration. kc On 2/25/12 11:07 AM, gor...@gordondunsire.com 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 On 25 February 2012 at 14:15 Karen Coylekco...@kcoyle.net wrote: On 2/24/12 6:38 PM, Thomas Baker wrote: To be clear, the definition of dc:subject would remain unchanged: The topic of the resource. No definitions would change. The change I am proposing is that the usage guideline -- that Coverage be used instead of Subject to describe the spatial or temporal topic of the resource -- be dropped. This does not mean that anyone would have to change what they are doing -- e.g., to start using Subject for describe spatial or temporal topics instead of Coverage. However, it is not incorrect to use Subject with a spatial or temporal topic, and removing the usage guideline would remove any ambiguity in this regard. But aren't the guidelines guidelines not rules? The question is not what is or isn't in the guidelines, but what we think is the best practice. Note that the *definition* of dc:coverage includes spatial and temporal *topics*. Are you saying that you wish for there to be two options for spatial and temporal topics? I think that removing the
Re: The meaning of Subject (and Coverage)
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 Periodhttp://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, gor...@gordondunsire.com gor...@gordondunsire.com 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;
Re: The meaning of Subject (and Coverage)
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
