[Seavox] Draft mapping

[John Graybeal]

Wow, Roy, looks intense.

I focused on a different part of Luis' comment perhaps, so I have a question for you and a question for him.

At 8:22 AM +0000 2/7/07, Roy Lowry wrote:
><snip>
>  In the example you quote, I am pretty comfortable that what I call 'chlorophyll pigments' and what GCMD calls 'chlorophyll' are exactly the same and what I call the 'water column' and what GCMD calls the 'hydrosphere' are exactly the same (oceans, seas, estuaries, rivers, lakes, puddles.....). 
>
>>BODC Chlorophyll pigment concentrations in the water column =??
>>GCMD EARTH SCIENCE > Hydrosphere > Water Quality/Water Chemistry > 
>>Chlorophyll

My question for you revolves around the term 'concentration'.  In CF they incorporate things like 'mass', 'concentration', and so on into the standard terms.  I'm wondering if someone had reason to create a BODC term 'chlorophyll pigment mass in the water column', would this reflect a different set of resources than the pigment concentration term, thereby suggesting a broad-match rather than exact-match.

>An interesting quandry I've encountered is wehere a term has two components that have opposing relationships.  For example consider:
>
>nutrients in the ocean
>nitrate in the water column
>
>'Nutrients' is boader than 'nitrate' but 'ocean' is narrower than 'water column'.  In these cases I've adopted the view that the phenomenon dimension is more important than the spatial dimension and so would map 'nutrients in the ocean' broader than 'nitrate in the water column'.  Alternative viewpoint welcome.

It all depends on what's more important to the applications that use your relationships, doesn't it?  Your approach seems a good guess.

By the way, I agree that literally 'water column' should be broader than 'ocean' (and I'd be tempted to push back against the vocabulary that used 'ocean' as the reference, unless it was intentional).  But here's how I might finesse this to make them "equal":  *If* the  'nutrients in the ocean' concept appears _only_ in a context of ocean observations -- so there is never any chance of a different concept showing up (in that vocabulary) of 'nutrients in fresh water' or 'nutrients in the water column' -- then I would argue that the spatial dimension of the two terms is semantically equivalent.  That is, as far as the users of 'nutrients in the ocean' are concerned, they *are* dealing with 'nutrients in the water column', because that's the only water they experience.

The flaw in that reasoning is that there is some information loss, such that someone deliberately excluding ocean measurements from their nutrient search will not be able to exclude this set of data, because it's been related to water column. (The corresponding benefit, however, is that any estuarine waters that got erroneously labeled 'ocean', because that was the only available term, will now be discoverable.)  Of course, in the labeling that you've used the same problem occurs, so maybe it comes with the territory.

You'll notice how much I'm incorporating suspected and assumed human behaviors into my thinking. :->

My question for Luis is whether there is a SKOS relationship that reflects this intersection of properly indexed resources, where the two overlap but neither subset or superset relationships exist.  That would be a useful representation of the real world in your case, but I suspect it doesn't provide the proper inference behaviors for SKOS to have used it....

John



> >>> Luis Bermudez <bermudez at mbari.org> 2/6/2007 10:27 pm >>>
><snip>
>3) About broader and synonym, SKOS defines the following:
>
>- If 'concept A has-broad-match concept B' then the set of resources 
>properly indexed against concept A is a subset of the set of 
>resources properly indexed against concept B.
>
>- If two concepts are an 'exact-match' then the set of resources 
>properly indexed against the first concept is identical to the set of 
>resources properly indexed against the second. Therefore the two 
>concepts may be interchanged in queries and subject-based indexes.
>
>My concern is that we have to be very careful about synonyms or 
>"exact-match", for example:
>
>BODC Chlorophyll pigment concentrations in the water column =??
>GCMD EARTH SCIENCE > Hydrosphere > Water Quality/Water Chemistry > 
>Chlorophyll

-- 
----------
John Graybeal   <mailto:graybeal at mbari.org>  -- 831-775-1956
Monterey Bay Aquarium Research Institute
Marine Metadata Initiative: http://marinemetadata.org   ||  Shore Side Data System: http://www.mbari.org/ssds