[tdwg-content] FW: [STDTRK] Request for a Decision for Public Review of DarwinCore Draft Standard

Donald Hobern dhobern at gmail.com
Wed Aug 26 03:20:02 CEST 2009

Thanks, John.

I must still be missing something on the definitions of Event, etc.  Where
are the definitions you quote below?
http://rs.tdwg.org/dwc/terms/type-vocabulary/index.htm has definitions like
the rather circular "A resource describing an occurrence" and the cryptic "A
non-persistent, time-based occurrence" - which raises a whole new problem
because (at least as I understand it) "occurrence" in this definition means
something more general than "occurrence" as used for the Occurrence resource

As for the question whether examples or lengthier definitions would be good,
I tend to think that in Dublin Core world, examples would only be a sample
of possible uses within the range intended by a definition and that they may
therefore help to steer people towards appropriate use but cannot introduce
any constraints which could help us to tighten up cross-resource data
integration.  The scientific name example is a clear case.  I have a feeling
that the semantics for this element as it stands right now (spanning
Occurrence and Checklist uses) imply a very general definition like "the
scientific name which is connected with this item" with the nature of that
connection unstated or at best covered by an implicit "it should be obvious
in each case what we expect to see in this field".  I admit that abuses of
this term to do things we don't expect seem unlikely - someone giving
ScientificName="Homo sapiens" because that is the scientific name for the
collector, or something.  However the laudable wish not to over-restrict the
use of these terms does have the corollary that consumers of data always
have to be aware that a provider may use the terms in semantically
incompatible ways.  If we knew that Occurrence->ScientificName was defined
to mean something like "the scientific name used for the most refined taxon
concept to which the specimen or observation has been identified", and that
Occurrence->DecimalLatitude and Occurrence->DecimalLongitude related to the
site at which the observation was made or the specimen was collected, we
would more or less have a contract that Occurrence records containing a
ScientificName, Latitude and Longitude were explicit assertions that an
individual of the given taxon concept had indeed been found at those
coordinates.  If we have no assurance that the ScientificName relates to the
identification of the specimen/observation, or that the coordinates relate
to the observing/collecting site (rather than say the coordinates for the
collection building), we always have some latent uncertainty about what is

Very best wishes,


-----Original Message-----
From: gtuco.btuco at gmail.com [mailto:gtuco.btuco at gmail.com] On Behalf Of John
Sent: Wednesday, 26 August 2009 10:52 AM
To: Donald Hobern
Cc: tdwg-content at lists.tdwg.org
Subject: Re: [tdwg-content] FW: [STDTRK] Request for a Decision for Public
Review of DarwinCore Draft Standard

Finally getting around to some older messages in an effort to finish
up the public review of Darwin Core.  Comments inline.

On Sun, Jul 26, 2009 at 6:03 PM, Donald Hobern<dhobern at gmail.com> wrote:
> At Gail's request, I'm forwarding some discussion between Renato and
> on the Darwin Core draft
> Thanks,
> Donald
> Renato,
> You are quite right - domains and ranges may cause us more problems.  At
> very least it may be sensible for these to be things which get asserted
> within other OWL files used within specific projects to govern their own
> application models and inference rules.

Domains have been removed for all terms. A new attribute
"organizedInClass" is used for term organizational maintenance.

> In the end my concerns are really around the need for more clarity on the
> way that the dcTerms:type values are to be used and how this relates to
> use of Darwin Core.  I'm not sure I ultimately disagree with any of the
> decisions made.  However I still cannot find any actual definition for the
> Occurrence and Event cases to explain what situations they are intended to
> cover.  Unless we take the time to define the intended scope for all our
> terms and property values, it is hard to predict whether data from
> sources can be expected to be suitable for combination.

I agree that there a great challenge for the new Darwin Core will be
to make sure that publishers and consumers do not mix apples with
oranges, unless their particular use case warrants doing so.

What is missing from the explanations at
http://rs.tdwg.org/dwc/terms/type-vocabulary/index.htm? Or from the

Event - The category of information pertaining to an event (an action
that occurs at a place and during a period of time).

Occurrence - The category of information pertaining to evidence of an
occurrence in nature, in a collection, or in a dataset (specimen,
observation, etc.).

dcmitype:Event - A non-persistent, time-based occurrence. For Darwin
Core, a resource describing an instance of the Location class.

dwctype:Occurrence - A resource describing an instance of the Occurrence

> The scientific name case is one example.  I would like an explicit
> that it means nothing more than "the name of a taxon (somehow) associated
> with this record" rather like a Dublin Core subject.  If, e.g. in the case
> of an Occurrence record, it is meant to be a statement that a taxon was
> actually recorded at the location on the given date, we may need to be
> explicit.  I'm still not comfortable with leaving these things unstated.

Would clarity be best served by examples? Or by lengthier definitions?
I have adopted the Dublin Core tendency toward brevity wherever
possible, not pretending to know the scope of usage of a term in the
long run. We have the supplementary wiki at our disposal to clarify as
much as necessary. It has only just begun to be filled with useful
material that I happened to feel qualified to provide based on my
experience. I think we could do a lot more with it, and not affect the
standard while doing so.

> I must however emphasise that I am very happy to see how much work has
> into this revision and the level of forethought in addressing many
> issues.

Much appreciated, sincerely.


> Donald
> -----Original Message-----
> From: renato at cria.org.br [mailto:renato at cria.org.br]
> Sent: Friday, 24 July 2009 7:04 AM
> Subject: RE: [STDTRK] Request for a Decision for Public Review of
> Draft Standard
> Hi Donald,
> Scientific name is precisely the kind of term that I feel should be
> generic. There's an ancient search interface at CRIA that illustrates the
> use case "give me everything you have related with this scientific name":
> http://names.cria.org.br/index?lang=en
> (check all checkboxes at the bottom of the page)
> In SPARQL I think the query would simply look like:
> WHERE { ?x  <http://rs.tdwg.org/ont/scientificName>  "some name" }
> instead of repeating the same condition for every possible combination of
> domain#property.
> Most id properties (collectionID, locationID, etc.) should also probably
> be "domainless" since they can appear in objects from many different
> classes.
> Best Regards,
> --
> Renato
>> Looking at what is in the DwC document, I think my concerns are with
>> plans to use DwC for checklist data rather than the DwC proposal itself,
>> but the problem issue may be in there somewhere.  Here are some comments
>> sent earlier:
>> I need to take some time and provide some comments on the use of Darwin
>> Core for non-occurrence data.  In general I believe we need to be moving
>> towards simple class properties with tightly defined explanations of the
>> expected content and format.  This use of DwC seems to me to be a
>> significant dilution of the semantic content of these properties.  If DwC
>> is an object property just for a taxon occurrence, the explanation of
>> dwc:ScientificName would be something like "The scientific name assigned
>> to the taxon to which the recorded organism was identified".  If we
>> it to cover taxon occurrences, checklist entries and all the other things
>> that people seem to have in mind, the explanation would reduce to "The
>> scientific name which is associated with this record".  In practice few
>> people will be stumbled, but I really don't like it.  It would be so easy
>> just to have chk:ScientificName as well as dwc:ScientificName and to keep
>> the semantics explicit. This becomes particularly problematic when we
>> play with RDFS and OWL. We could choose to define the
>> property to have a domain restricted to TaxonOccurrence, allowing a
>> reasoner > to infer that objects with this property can be treated as
>> TaxonOccurrence records.  With the diluted dwc:ScientificName all we can
>> infer is that the object is a
>> ThingWithSomethingToDoWithTheBiologicalDomain.
>> Donald
> --
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