about #calibration (VEP-006) : ----> IMPORTANT for DataLInk EXTENDED USAGE

[Markus Demleitner]

Dear François,

On Fri, Oct 08, 2021 at 07:06:31PM +0200, BONNAREL FRANCOIS wrote:
> Le 07/10/2021 à 15:24, Markus Demleitner a écrit :
> > Based on this, could you then explain as clearly and concisely as you
> > can why VEP-006 impedes that use case?
> 
> A user discovers a calibrated image (HST, ESO, etc...) . With DataLink
> (#this or #preview) she has a look to the image and want to see how the
> uncalibrated data and the flat field looked like to understand some of the
> features. DataLink provides  a link to the #progenitor and also (by some
> record the semantics of which cannot be anymore "calibration or #flat) to
> the flat field, etc... used to calibrate this progenitor.

...but for this use case there is no need to distinguish between what
you call a progenitor (i.e., non-calibration part of provenance) and
calibration files applied.  Right?

Plus: A client can already do that, no?  If you think not: What do
you see missing?

> Client software is intended to display all these images (science and
> calibration) together for checking and comparison. Moreover an advanced
> version could poropose some kind of reprocessing of progenitor.

Not that that has any relationship to VEP-006 at all, but we have
provenance for a detailed description of how the various pieces of
the provenance chain play together; we certainly do not want to
re-model that in the datalink vocabulary.  It's been compicated
enough to do that modelling once.

> Where VEP-006 "impedes" that is by letting the "already applied" use case
> orphan.  We have no more terms to qualify the calibration files used this
> way. With the new definition we can only apply the calibration files to the
> discovered image itself (#this in DataLink), and not to the progenitor

As stated multiple times, VEP-006 is entirely unconcerned with this
problem.

First, we don't have any such links now, so nothing is orphaned at
this point.  And I maintain it would be prudent to wait until we
actually have such links, as the motivation of people publishing such
links will inform us if what we think is sensible behaviour (the
"pragmatics") actually is in the view of the data providers.

Second, the current #progenitor is clear that if there were any
"Calibration applied" links, they would be covered by its concept; see
its description: "data resources that were used to create this
dataset (e.g. input raw data)".  You may not like the concept or its
label, but we have VEP-009 to discuss that.  

The relevant point here is: VEP-006 in no way predetermines whether
we do nothing at all about "Calibration applied" (full disclosure: I
think that's the right choice), whether we create a child of
#progenitor (perhaps after fixing its label) or whether we change its
meaning and create a sibling of it.  Or whether we do something
entriely different, depending on what the pragmatics turns out to be.

If you disagree on this assessment: How would VEP-006 influence this
deliberation?


So, again, please let's not mix up all these different discussions.
We will never get anywhere in semantics if we do.

Everyone but François: Do you, as François alluded to, still have
concerns with VEP-006?.

If not, François, can you at least agree to: "I think VEP-006 is
wrong, but I'll not veto it"?

            -- Markus