Trevor - thanks very much for your comments and comparative document - this is really useful, and we need to get much more feedback like this.

The main difference between SDD and Prometheus seems to be that you are working specifically on the basis of defining a controlled terminology whereas SDD explicitly decided early on that a controlled terminology was outside our scope. History will judge which approach is best.

We did have early discussions about a controlled terminology (see the list archives for a history of this).One dificulty for us is that SDD is designed to be biology-wide (indeed, we have even removed specific references to biology, such as "taxon", because SDD is equally applicable to descriptions of non-taxa such as diseases, nutrient deficiency syndromes, soils and minerals. Perhaps here we have drawn our bow too wide, but we were informed by the fact that at our Lisbon meeting all but one of the contributors who were working with identification tools had removed their biology-specific tags to become more general). Prometheus (as I understand it from your document) is specifically botanical. This would be an intolerable restriction for us given our brief.

Obviously, a botany-wide controlled terminology is more achievable than a biology-wide one. Personally, however, I think that you run the danger even in botany with any controlled terminology of trying to force nature kicking and screaming into small boxes, and do it an injustice therewith. I don't know how any botany-wide controlled terminology could cope with the leaves of Drosera auriculata, for instance, or the morphology of Podostemaceae. (In fact, I wonder whether the dream of a controlled terminology is more likely in a cold Northern Hemisphere climate than in the biodiverse South or tropics?).

In general, we have taken the view that a controlled terminology in particular domains (e.g. legumes) may develop as an emergent property of SDD, rather than imposed top-down.

On more specific points from your document:

Complexity: SDD was scoped to be a superset of existing systems and standards e.g. DELTA, Lucid, DeltaAcess, and also to accommodate future developments that those of us working in the field can envisage but no-one's really done yet (particularly federation issues - and you may be further down this track than we are). This is part of the reason for the complexity,

It is not clear to me whether SDD is proposing this schema as a unifying schema to which different description formats would map their own schema or whether the SDD schema is being proposed as a schema for developers to (partially) implement when designing applications >and repositories for capturing descriptive data.

It is designed as a unifying standard, to allow lossless roundtripping between applications. At the same time, we are struggling with how much should be mandatory and how much optional (your second option)

...

...

From our own collaborative experiences with botanical taxonomists, data models and structures hold no interest to them in >practice, and they find even our simple conceptual model of character description complex to understand. Probably few working >taxonomists would wish to interact at any level with the SDD schema and applications would have to achieve this mapping >transparently.

On this I'm sure you're right, and we have had many discussions within SDD about this problem. There are differing views as to the importance of taxonomists themselves coming to grips with SDD, as the standard itself will generally be invisible to a taxonomist using an SDD-compliant application.

Translation and multiple language representations: allowing multiple languages is seen as a fundamental part of the SDD brief. Life would indeed be much simpler if everyone spoke the same language, but they don't so we need to handle that.

It is not clear whether SDD proposes that a single document can include multiple language representations, or whether these >would form separate documents, conforming to the same standard

SDD can handle multiple language representations of every character string within the one document.

Multiple expertise levels

I am similarly suspicious of the necessity for including the ability for recording different expertise levels in one document format. >Is SDD proposing/allowing multiple representations within the same document : or just that the same format/standard can be >used for documents aimed at different expertise level.

There clearly is value in being able to extract/translate simple language descriptions from complex data resources - as is >necessary for compiling flora and keys from monographs and original descriptions. However, is including the ability to describe >descriptive data in language suitable for primary schoolchildren relevant to an accurate scientific database of taxonomic data. [Again this would appear to be a political requirement??]

----- Original Message ----- From: Paterson, Trevor To: TDWG-SDD@LISTSERV.NHM.KU.EDU Sent: Monday, March 15, 2004 9:41 PM Subject: SDD Schema in relationship to Prometheus

Gregor

I have written a rough document considering several aspects of the SDD-schema - largely interpreted with reference to our Prometheus Database model for descriptive data. It seems easier to keep this all together, rather than post it to various sections on twiki, so i am attaching it here

My main problems in interpreting the schema were the lack of documentation ( as always...) especially for the conceptually complex parts like concept trees. I think clear, visual summary models for description, characters, concept trees etc would help a novice to get to grips with the concepts, and might make some of the complexities more tractable. I do worry that the overall schema is over complex and 'trying to do too much in one go' - eg considering multiple language and expertise representations, although I am sure that there are good political reasons for everything.....

yours trevor

Trevor Paterson PhD t.paterson@napier.ac.uk

School of Computing Napier University Merchiston Campus 10 Colinton Road Edinburgh Scotland EH10 5DT

tel: +44 (0)131 455-2752

www.dcs.napier.ac.uk/~cs175 www.prometheusdb.org