The example 2.4% is a string, but the definition is the same as the proposed abundance term. I think it should instead be something like " A string produced by computing 100 times the number of individuals of a taxon found in a sample divided by the total number of individuals of all taxa in the sample, converting that real number to a string and concatenating '%' to the result." One way or another, denovo properties with the same semantics and also permitting the same datatype should be avoided, especially where easy.
A W3C working group on RDF validation is being proposed based on a recent workshop on that subject [1]. Having been at part of that workshop, I've come to think that whenever easy, term definitions should seek to minimize ambiguities WRT to valid values of properties. It's low-hanging fruit to specify that a datatype property not accept a union of types, and here even specifying that a value of "2.4" as a string still needlessly carries validity checking risks, e.g. in serializations like RDF/XML which might trip on the issue. At a minimum the abundanceAsPercent should declare a (single) datatype, probably a string type.
[1] https://www.w3.org/2012/12/rdf-val/report
On Wed, Sep 25, 2013 at 8:35 AM, John Wieczorek tuco@berkeley.edu wrote:
Dear all,
GBIF has just published "Meeting Report: GBIF hackathon-workshop on Darwin Core and sample data (22-24 May 2013)" at http://www.gbif.org/orc/?doc_id=5424. Now that this document is available for public reference, I would like to formally open the minimum 30-day comment period on two related new terms proposed during the workshop and defined in the referenced document.
The formal proposal would add the following new terms:
Term Name: abundance Identifier: http://rs.tdwg.org/dwc/terms/abundance Namespace: http:/rs.tdwg.org/dwc/terms/ Label: Abundance Definition: The number of individuals of a taxon found in a sample. This is typically expressed as number per unit of area or volume. In the case of vegetation and colonial/encrusting species, percent cover can be used. Comment: Examples: "4 per square meter", "0.32 per cubic meter", "24%". For discussion see http://code.google.com/p/darwincore/wiki/Occurrence (there will be no further documentation here until the term is ratified) Type of Term: http://www.w3.org/1999/02/22-rdf-syntax-ns#Property Refines: Status: proposed Date Issued: 2012-03-01 Date Modified: 2013-09-25 Has Domain: Has Range: Refines: Version: abundance-2013-09-25 Replaces: IsReplaceBy: Class: http://rs.tdwg.org/dwc/terms/Occurrence ABCD 2.0.6: not in ABCD (someone please confirm or deny this)
Term Name: abundanceAsPercent Identifier: http://rs.tdwg.org/dwc/terms/abundanceAsPercent Namespace: http:/rs.tdwg.org/dwc/terms/ Label: Abundance as Percent Definition: 100 times the number of individuals of a taxon found in a sample divided by the total number of individuals of all taxa in the sample. Comment: Examples: "2.4%". For discussion see http://code.google.com/p/darwincore/wiki/Occurrence (there will be no further documentation here until the term is ratified) Type of Term: http://www.w3.org/1999/02/22-rdf-syntax-ns#Property Refines: Status: proposed Date Issued: 2012-08-01 Date Modified: 2013-09-25 Has Domain: Has Range: Refines: Version: abundanceAsPercent-2013-09-25 Replaces: IsReplaceBy: Class: http://rs.tdwg.org/dwc/terms/Occurrence ABCD 2.0.6: not in ABCD (someone please confirm or deny this)
The related issues in the Darwin Core issue tracker are https://code.google.com/p/darwincore/issues/detail?id=142 and https://code.google.com/p/darwincore/issues/detail?id=187
If there are any objections to the changes proposed for these new terms, or comments about their definitions, please respond to this message. If there are no objections or if consensus can be reached on any amendments put forward, the proposal will go before the Executive Committee for authorization to put these additions into effect after the public commentary period.
Cheers,
John _______________________________________________ tdwg-content mailing list tdwg-content@lists.tdwg.org http://lists.tdwg.org/mailman/listinfo/tdwg-content