In the context of developing the DwC RDF Guide and trying to maintain consistency with Audubon Core, I have written on the subject of various license-related terms [1]. In particular, I discuss the implications of various subproperty relationships that have been asserted for several common license-related terms, such as cc:license, xhv:license, and dcterms:license.
I should note that the issue that Bob brings up also applies to dcterms:license because dcterms:license is rdfs:subPropertyOf dcterms:rights. [2] So suggesting a license URI as a value for dcterms:rights can't be "wrong" because a reasoner could infer that triple anyway based on the subproperty relationship.
An additional issue is the fact that the range of dcterms:license is dcterms:LicenseDocument, a non-literal class. [2] So it would be best to NOT use that term with a string literal. In the RDF Guide[3], we recommend using legacy dc: namespace terms (where they exist) with literal values [4] in cases where DCMI declares non-literal ranges for dcterms: namespace terms. Unfortunately, there is no dc: namespace analogue for dcterms:license. Because dcterms:license was not part of Darwin Core when the guide was written, there is no suggestion for a literal value analogue to dcterms:license in the guide itself. But following the lead of Audubon Core, the ancillary document [1] suggests that the term xmpRights:UsageTerms could be used as a literal value alternative to dcterms:license. I would be interested in hearing opinions about whether this suggestion is appropriate or not. The ancillary document is informative and not part of any standard so it can easily be changed to reflect any consensus about what we consider to be a best practice.
Steve
[1] http://code.google.com/p/tdwg-rdf/wiki/LicenseProperties [2] http://dublincore.org/documents/dcmi-terms/#terms-license [3] http://code.google.com/p/tdwg-rdf/wiki/DwcRdfGuideProposal [4] http://code.google.com/p/tdwg-rdf/wiki/DwcRdfGuideProposal#3.3_Imported_Dubl...
John Wieczorek wrote:
Dear all,
Bob Morris recently submitted an issue [1] to the Darwin Core code site showing a potential ambiguity in the inclusion from Dublin Core of both dcterms:rights and dcterms:accessRights in the Simple Darwin Core schema [2]. The ambiguity arises from the fact that dcterms:accessRights is actually a subclass of dcterms:rights.
Looking at the Darwin Core documentation about the use of these terms, I noticed that dcterms:rights [3] suggests a license ("http://creativecommons.org/licenses/by-sa/3.0/") as an example. I think this example is an inappropriate use for the term and instead is an example of a dcterms:license.
I think it would be a good idea to add dcterms:license to the list of terms promoted by Darwin Core, especially after reading Peter Desmet's blog posts [4, 5]. If license was indeed the intent for including dcterms:rights in the first place, then perhaps it can be deprecated, leaving only its subtype dcterms:accessRights.
Discussion welcome, so that I know whether to submit an issue for these changes to the Darwin Core.
Thanks,
John
[1] https://code.google.com/p/darwincore/issues/detail?id=196 [2] https://darwincore.googlecode.com/svn/trunk/xsd/tdwg_dwc_simple.xsd [3] http://rs.tdwg.org/dwc/terms/index.htm#dcterms:rights [4] http://peterdesmet.com/posts/illegal-bullfrogs.html [5] http://www.canadensys.net/2012/why-we-should-publish-our-data-under-cc0 _______________________________________________ tdwg-content mailing list tdwg-content@lists.tdwg.org http://lists.tdwg.org/mailman/listinfo/tdwg-content