Necessity of ActivityDescription [was: IVOA Provenance DM -RFC- answers to comments]

[Markus Demleitner]

Hi Mirelle,

On Mon, Nov 26, 2018 at 07:36:51PM +0100, Mireille LOUYS wrote:
[converted to inline quoting]
> Le 26/11/2018 à 13:01, Markus Demleitner a écrit :
> > On Sun, Nov 04, 2018 at 08:26:09PM +0100, Mireille LOUYS wrote:
> > > we need the ActivityDescription class and Parameter class to be able to
> > > search for some specific processing type on the data.
> > > Activity is only the process launched for the computation.
> > > It does not hold the details of the methods , because those details are
> > > factorised in the ActivityDescription class.
> > You mean "Find me all source extractions being done on the images of
> > this data collection"?  That *does* sound like a fairly basic thing to
> > want to do, yes, and from what I see in the current Activity model, it
> > would, indeed, seem to be impossible just with what's there.
> > 
> > I'm sure the W3C has a plan for this -- do you know what it is?  Can't
> > we just follow them or is there a use case we have they don't?

> The Prov-W3C is providing the general framework , and the concepts.  In
> practice, for each application domain one needs to bring more information
> about the usage , rules, specificities.

Yes, sure, but there are different ways to do that, right?  

For instance, to cover your use case I'd (probably naively) have said
"let's start with a simple, string-valued operationType attribute on
the Activitiy and see that we have a controlled vocabulary for the
types of activities out there" -- in which case you could even have
interoperable clients for this use case (which, as far as I can see,
you can't with an open ActivityDescription).

My question was essentially: Have people (in other communities, I
guess) tried such a thing?  If so and if it worked, are our problems
really structed so differently that we need to go into the complexity
of ActivityDescription and everything that comes with it?

         -- Markus