[taxon-model] Re: Owl polymorphism

Markus Döring m.doering at bgbm.org
Fri May 11 16:47:30 CEST 2007

Im not sure why we are talking about inheritance.

My primary goal is to see how useful TDM is for data exchange and  
integration. I am very interested for example to use TDM to exchange  
species distribution data. If every application defines its own  
occurence status terminology noone would be able to merge datasets.  
So I was hoping TDWG would at least define a default standard for  
those kind of things. I am aware that some communities will use a  
different standard, but if they want to be interoperable with the  
outside world how can you see this happen if we dont define a common  
terminology? Reason over hundreds of SameAs statements? It would be  
nice to have at least a standard "backbone" where you can relate your  
terminology against.

And if we agree that this is needed, why not have a strongly typed  
property for the respective InfoItem classes that only allows terms  
of the recommended terminology? But maybe I misinterpreted the  
purpose of TDM and/or are still too heavily influenced by xml schema ;)


On 11.05.2007, at 13:56, Bob Morris wrote:

> Alas, for some of the intended audiences, there are requirements of
> practice, or even of law, to use particular controlled vocabularies.
> Often, there are several in wide use. This is especially true in the
> invasive species community, but also, I believe,  for many
> agriculture, public health and other communities.
> My inclination is to share Roger's concern about an inheritance tree
> adding complexity that might add to the complexity of either
> application building or adoption. (I can't believe I'm agreeing with
> Roger in this domain... :-)  ).  Unfortunately, my intuition is that
> two related problems will quickly arise:
> (a). The inexperience, and a small stake in the outcome, of the
> various communities will quickly lead to an undisciplined inheritance
> tree in which most people derive from the base, not from other
> derivations. This in turn makes effective and easily extended
> polymorphic application programming difficult or impossible to put in
> place.  If the utility of polymorphic programming is compromised,
> there seems small point accepting the maintenance hit of polymorphic
> ontology. It's a little like the difference between tags and property
> lists. You can go an awfully long way with the former even though they
> just float by like clouds.
> (b)For similar reasons to (a), even when disciplined extension
> lineages emerge, there will be rooted  at them further undisciplined
> derivations as above, and that these will lead to \semantic/
> multipaths through the inheritance trees as people map undisciplined
> leaf nodes in one branch to those in another.
> For a number of the TDMTerm categories there are already multiple well
> established controlled vocabularies. Many of the relevant
> subcommunities are communities of practice, not of theory, and feel
> more constrained to "get on with it" about their work than to make
> sure it is easily related to the vocabularies of other subcommunities
> much less apparently unrelated communities. I believe this is
> especially true where ecology, public policy, commercial or health
> data are in play. It is a little regrettable that the list and wiki
> name got abbreviated from Taxon Data Model to Taxon Model. The latter
> might give taxonomists the mistaken (I hope) view that TDM is about a
> theory of what a Taxon is.
> On 5/11/07, Markus Döring <m.doering at bgbm.org> wrote:
>> Roger,
>> this was not targeted directly at TDM. I was mainly exploring OWL and
>> definitely not suggesting multiple inheritance!
>> But in regards to TDM I was thinking about the consequences of
>> allowing any defined term as a "controlled" value for
>> InfoItems.hasValue.  Is this desired? Having individual classes for
>> the InfoItem categories now would allow us to define a specific
>> controlled vocabulary for each category - or None if we dont think
>> this is a good idea. These vocabularies, like CyclicityTerm, can
>> easily be extended by anyone who really needs to. And all InfoItems
>> are allowed to contain uncontrolled values via the hasContent
>> property in any case.
>> --
>> Markus
>> On 11.05.2007, at 11:30, Roger Hyam wrote:
>> >
>> > Hi Markus,
>> >
>> > Sounds like interesting and complex stuff and exactly what I am
>> > trying to avoid ;)
>> >
>> > If this is for exchange standards we want to keep things as simple
>> > as possible. We also need our ontology to entail as little as
>> > possible so people can understand it and (if they are up on the
>> > technology) import it into their own business ontologies.
>> >
>> > The role of the exchange ontology is to denote the meaning of
>> > simple fields it is not to enable connotations but to avoid them.
>> >
>> > This is why I was sticking to simple properties with domains and
>> > ranges. Really just one up from RDFS. If it is important for a
>> > consumer to assert a hierarchy of properties then they can do that
>> > in their own ontology and import it. Who is to say that all
>> > consumers will have the same notion of that hierarchy and what is
>> > the business case for trying to impose one at this point?
>> >
>> > If there were polymorphism of properties (overriding them in sub
>> > classes) then it would get confusing because of the multiple
>> > inheritance. I am not sure what would happen to meaning with the
>> > diamond problem - where the same property is inherited via several
>> > routes but has it's meaning changed differently on each route.  It
>> > is always possible to subclass the property though and it may be
>> > possible to forbid the use of the parent property in a class -
>> > perhaps - but this is getting beyond my reading level.
>> >
>> > Not sure if this helps,
>> >
>> > All the best,
>> >
>> > Roger
>> >
>> >
>> >
>> >
>> > On 11 May 2007, at 09:54, Markus Döring wrote:
>> >
>> >> Roger,
>> >> is it possible with OWL to have polymorph class properties?
>> >> As properties are global and only bound to classes via range/
>> >> domain it doesnt seem to be possible to me, but maybe Im wrong.
>> >> Can I redefine a propertys range depending upon the class it
>> >> belongs to, so its domain? Well, that would mean to declare the
>> >> same property twice with different domains and ranges. Probably
>> >> impossible. It is different from classic OO thinking...
>> >> --
>> >> Markus
>> >>
>> >>
>> >>
>> >
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