The product-type vocabulary

[Dave Morris]

Hiya,

The proposed vocabulary mixes singular and plural terms.

The term is event (singular), but the label and description are for 
eventS (plural).

In VOEvent it is possible to have both a single event, equivalent to a 
row in a database table, and a stored collection or live stream of 
events.

Most of the other terms are singular, cube, image, spectrum, 
time-series, visibility etc. but measurementS is plural.

The example use-case given in the description of the vocabulary uses the 
plural term "spectra" in the discovery query, but the target term in the 
vocabulary, "spectrum", is singular.

     "... to facilitate by-product discovery (“find spectra”) and is 
intended to cover similar use cases elsewhere (e.g., “find services 
serving spectra” in Registry)."

The example use-case in the interop talk is searching for the singular 
term:

     SELECT
         TOP 30 access_url
     FROM ivoa.obscore
     WHERE
         1=gavo_vocmatch(
             ’product-type’,
             ’spectrum’,
             dataproduct_type
         )


Suggest we keep it simple and always use the singular term, even when 
referring to a collection.

Handling synonyms and plurals is probably a separate step from defining 
the core vocabulary.

So a discovery query for a collection of images would search for 'image' 
and a query for a collection or stream of events would search for 
'event' as the product type.

Hope this helps,
-- Dave


--------
Dave Morris
Research Software Engineer
Wide Field Astronomy Unit
Institute for Astronomy
University of Edinburgh
--------

On 2021-12-15 08:03, Markus Demleitner wrote:
> Dear Semantics, Dear DAL,
> 
> The current Datalink WD
> (http://ivoa.net/documents/DataLink/20211115/index.html) needs a
> vocabulary of product types (images, spectra,...), mainly to satisfy
> the "figure out a client suitable as a SAMP target" use case.
> 
> While there are other use cases (of course, dataproduct_type in
> obscore, but perspectively also searching by the sort of data
> products coming out of a service in the Registry), because of the
> Datalink WD review I'd say it's up to DAL to bring this vocabulary
> into shape.
> 
> I've published a draft of this at
> <http://www.ivoa.net/rdf/product-type>, which basically reflects the
> word list used by obscore, plus #dynamic-spectrum at the request of
> the SSIG.
> 
> I had talked about that re-design at the last Interop,
> <https://wiki.ivoa.net/internal/IVOA/InterOpNov2021Sem/product-type.pdf>
> -- if you've not been there, briefly skimming the notes might help
> understanding where this is going.
> 
> By Vocabularies rules, as long as the vocabulary is preliminary,
> terms can be easily added and removed (though in this case I'd say we
> shouldn't remove anything coming from obscore, although I have to say
> I'd rather not have #measurements in its current shape).  If you have
> proposals in either direction, feel free to bring them forward here.
> 
> Thanks,
> 
>           Markus