Hi Nco,

   So we seem to agree on something like this:

Rich                                    Nico taxon name usage   <===>   "shallow" taxonomic concept taxon concept         <===>   "deep" taxonomic concept

Not quite. They're all based on TNUs. I would represent it more like this: TNU without well-defined concept <===> "shallow" taxonomic concept (aka "potential taxon" sensu Berendsohn) TNU with well-defined concept <===> "deep" taxonomic concept

Both: labeling is via name sec. author

Labeling of what? Should "sec." (or whatever abbreviated term I used) mean simply "this author used this name", or should it be restricted to mean "this author used this name in a way that was accompanied by a well-defined taxon concept circumscription"? In my discussions with various folk on questions related to GNUB & ZooBank, there seems to be a preference for "sensu" rather than "sec".

Both: authoring concepts/usages vs. identifying to those => slippery issue; ideally requires proper speaker awareness.

Agreed -- this is where the assertions are needed. In the case of nomenclatural acts, we have robust Codes that prescribe specific criteria for what nomenclatural acts are, and thus there is a (mostly) objective mechanism for recognizing which among the entire universe of TNUs are associated with nomenclatural acts (and, hence, which should be registered as such). However, there is no universally adopted "Code of Taxon Concepts" that outline such criteria, to determine which TNUs are accompanied by sufficiently robust concept circumscription definitions, and which are merely non-concept TNUs. I think it would be a mistake to attempt to define such a Code -- (similar problem to the "what is a species" issue).

 Why the latter? - well, because (again) the desirable effect of using concepts - the desirable situation where these would have a justification that goes beyond just really meticulous data management and advances to the level of facilitating better science qua more precise taxonomic semantics - only obtains if a great number of name occurrences in a wide range of shallow-ish sources is linked via identification to a presumably smaller number of occurrences where those names are well defined and where successive definitions of names are semantically linked. So there needs to be an emerging culture of minimizing concept inflation. Otherwise we obtain what we have now (mostly just names) and on top of that add new baggage (lots of really shallow concepts) that nobody can do good semantics with.

Agreed!

Here is where I think we disagree, perhaps just in terms of sales strategy:

   You seem to suggest that making an a priori distinction between TNUs and

concepts is (1) possible in a good number of cases, (2) is desirable perhaps in the form of registry, and (3) even necessary for building and populating databases, etc.

Sort of; but again, they're all based on TNUs. The issue is how to recognize which ones are associated with robust concept definitions, and which are not. So it's not about distinguishing between TNUs and concepts; it's about recognizing which TNUs include concept definitions, and therefore represent reference-points to concepts. I don't think this can be easily defined -- I think the only way to do it is by letting people assert it to be so. In other words, the definition of a TNU that represents a taxon concept is that someone says it is so. (Much like my own definition of a "species"!)

   Here I disagree, for a number of reasons. First off I do believe that not defining certain things too soon or too narrowly is sometimes actually really good science

By "certain things", do you mean "defining a particular TNU as having a robust concept definition associated with it"? Or, do you mean "defining what a taxon concept is, in general"?

and on the other hand, doing so can be a show stopper if other people don't share this narrowness and find it limiting.

I think I agree -- but until I understand what you mean by "certain things", I can't be sure.

Second, while we can perhaps readily agree that a lengthy monograph published in American Museum Novitates rises to the level of authoring next concepts

whereas a label saying "Family Carabidae" on a specimen submitted as part of an insect student collection does not, there are enough in-between cases where only time will tell.

Absolutely!! No disagreement here. The idea is not to say "this TNU includes a good concept definition". The idea is to say "this person asserts that this TNU is a good concept definition". I agree, we don't want to be too precise on drawing that arbitrary line. Indeed, I don't think it's possible to do so. Hence, the "Code of Taxon Concepts" is, I think, a bad idea (as stated above). Ultimately, the definition of a taxon concept is that someone says it is so.

   So this exemplifies IMO why so far the concept approach has been too abstract, the TCN has been too depauperate on the relationships/mapping side (worrying instead almost needlessness about what constitutes a concept per se), and definitions between identifications, name usages, shallow, deep concepts have been too abstract as well. I believe we should focus less discussion on those issues and more emphasis on building mapping tools that can carry a wide range of input and logically infer additional implied mappings from the initial expert-given set. The actual semantic properties of that input will emerge a posteriori and will be hard to predict in some cases. Some descriptions are lengthy but nobody understands them. Some names lists are profoundly informative if the context of their origin is well known to an expert.

I agree with all of this. I think it would be wise to post-pone the development of any sort of concept registry until the a posteriori analysis is done. Build the maps first (based on assertions from willing practitioners), then decide whether there needs to be a "registry" for which TNUs represent concepts, and which do not.

There will be some obvious overreaches in both directions (too many unconnected items, some items that are connected more precisely than their inherent information would seem to justify).

That is inevitable!

I think these overreaches would be tolerable. What's less productive to me is a restrictive set of definitions that provide an early blockage in they way towards an environment where mapping is supposed to occur very frequently.

Agreed.

We're not at the registry stage yet. More at the "can this work in principle" stage. As I mentioned before, the mappings ARE the concepts under a certain viewpoint. We don't want to pre-determine their fate by separating TNUs from concepts in a great number of cases.

Yes. I think we're on the same page -- just on different time scales. I was looking towards the end-game, but you're focused more on "where do we go from here". I agree that we should focus on your timescale first, and let the longer-term solution emerge from that.

   I hope this was not a misrepresentation of your view

Only slightly.... :-)

and also a clarification of my view. In the end, we both advocate some sort of balance for the same concerns, but perhaps disagree only strategically about the moment where/when that balance will materialize - upfront via precise definitions and registration or later on via the presence/lack of actual mappings.

Actually, I don't think we disagree on strategy. I agree with everything you describe above, and now feel that a registry of concepts is better thought of as a possible end-game. Better now to define a mechanism to allow people to make cross-reference assertions among TNUs, and let the issue of "what is a taxon concept" (specifically: which TNUs represent good taxon concept definitions) emerge from that. Aloha, Rich Richard L. Pyle, PhD Database Coordinator for Natural Sciences Associate Zoologist in Ichthyology Dive Safety Officer Department of Natural Sciences, Bishop Museum 1525 Bernice St., Honolulu, HI 96817 Ph: (808)848-4115, Fax: (808)847-8252 email: deepreef@bishopmuseum.org http://hbs.bishopmuseum.org/staff/pylerichard.html Note: This disclaimer formally apologizes for the disclaimer below, over which I have no control.