Warning to Tim: Go get your cup of tea before reading....
Hi Jerry,
I believe what you describe:
I think we do need an agreed way for identifying a 'set of name/article pointers' that define a useful grouping (which I would hesitate to call a concept). I don't think an open-ended linked data chain does provide that defined grouping.
...is already built into the GNUB data model.
Starting with a particular TaxonNameUsageID instance, we can directly get a set of Protonyms that are asserted in the Usage to be included within the taxon. From these Protonyms, we can explode out as far as you want to go.
The limitation, however, is that GNUB only includes the explict facts, not the interpreted meanings. In other words, we may know that Smith 1955 regarded Aus cus, Aus dus, and Aus eus as synonyms of Aus bus; but if he never mentioned Aus xus (either as another synonym, or as a distinct species) we can't know whether his circumscription of Aus bus would have included the type and implied other members of Aus xus. So, the facts alone don't cut it.
So if Smith treated Aus bus as follows (synonym indended below asserted valid name):
Aus bus L. - Aus bus L. - Aus cus Jones - Aus dus Brown - Aus eus Lamarck
And Pyle treated Aus bus as
Aus bus L. - Aus bus L. - Aus cus Jones - Aus dus Brown - Aus eus Lamarck - Aus xus Cooper
[without any mention of Smith's treatment of Aus bus]
...then we need a third party to assert whether or not "Aus bus sec. Smith" and "Aus bus sec. Pyle" are congruent.
With our new GNUB data model, we *could* represent these third-party assertions; but my gut feeling is that the third-party assertions should be external to the core GNUB model. But this is, of course, open for discussion.
Pete's point about the two different name/article intersections referring to the same 'concept' is resolved by the fact they are based on the same type, and that issue I prefer to see resolved at the nomenclatural level by protologue & type-collection pointers (as in the GNUB model).
Types don't do it for us. Using my example above, suppose we have DeVries' treatment of the Aus bus complex as follows.
Aus bus L. - Aus bus L. - Aus cus Jones - Aus dus Brown
Aus eus Lamarck - Aus xus Cooper
That is, he treated Aus bus and Aus eus as valid species, and included Aus xus as a synonym of the latter.
In all three treatements of Aus bus (Smith, Pyle, DeVries), the name "Aus bus" shares the same type -- but that doesn't mean that all three had the same taxon concept (circumscription).
So, in my mind, the real question is:
Do we need a separate "taxonConceptID" (as in the TDWG version of DwC) that we can use to brand the abstract Concept? Or are we able to assemble the same results from individual usage-instance mappings?
So, let's say that we are confident that Smith and Pyle both had the same idea for the taxon concept/circumscription of Aus bus (it's just that Smith forgot to list Aus xus in his synonymy). Do we need a single taxonConceptID to express the fact that they are the same taxon concept? Or can we derive that easily enough from a third-party assertion of the congruency of the concepts represented by the two usage-instances? Presumably we would also have separate taxonConceptID's for "Aus bus sec. DeVries", and for "Aus eus sec. DeVries".
I think it would help if we took a step back from using the term 'taxon concept' and agreed on what we are trying to achieve by linking/grouping the various constructs, and then arrive at a more precisely defined vocabulary for name/article intersections, and the open-ended universe of related stuff.
AGREED!!!
I suspect we will find that different end-user groups (e.g. hard core nomenclaturalists, nomenclaturally savvy taxonomists, most taxonomists, and the most important group ... non taxonomic savvy end-users of taxonomic services) all have differing and overlapping requirements, and a different understanding of the words being used.
NO DOUBT!
Despite my peripheral involvement in taxon concept space for many years I suspect the above comments reflect a deep seated blinkered view that stops me seeing how it should work given the existing vocabulary!
ME TOO! :-)
Rich