Re: Re-write of use case 48

Thanks, Rob. Note below under 1)

On 8/22/17 6:44 PM, Rob Atkinson wrote:
> Hi Karen
> 
> That's now formed as a Use Case :-)  We might need to think about the
> specific implementations as examples, rather than solutions.
> 
> a few points to consider:
> 
> 1) it is unlikely that a dataset conforms to "a profile" - rather it
> conforms to 0-N profiles - and these are sometime "hierarchical"
> specialisations - take for example NetCDF convention - CF extends COARDS [1]

This came up at the f2f, and probably needs more discussion. In general,
my understanding is that the group was not comfortable with "cascading
profiles" due to considerations like: having a profile fragment change
could mean it no longer describes your (static) dataset. However, it was
agreed that there would be "copying" of profiles or profile fragments
into new profiles that would be based on them.

Discussion is at
  https://www.w3.org/2017/07/18-dxwg-minutes#item06
use case 37.

This probably also relates to #4, below. I know that SHACL is developing
re-usable common patterns, but I haven't looked into how one is expected
to integrate those. In general, I think that SHACL (and ShEx) work fine
as atomistic rules, and I am hoping that profiles will provide a
coherent view of a usable set of data. The purposes are different.

(p.s. I referred to SHACL because it came up in discussion, and I had
the impression that some folks see it as a key aspect of profiles due to
the validation-like functions. I'm happy to not include it in this use
case.)

kc

> 2) distributions also conform to profiles - both for content and
> potentially service behaviours
> 3) SHACL is an RDF technology, but I dont see any reason why it cannot
> be applied to any structure if the mapping to RDF is predictable.  
> 4) multiple SHACL rules can co-exist and be re-used across different
> profiles - i would expect a profile to bind a set of appropriate SHACL
> rules - rather than be a large complex monolithic artefact
> 5) there is no reason to restrict validation rules to SHACL - some rules
> may be better expressed other ways - thus a profile is a collection of
> rules, and each rule should be associated with explanatory text.
> 6) rules should have identity and if two different languages are used to
> express the same rules this should be easily detectable
> 7) rules may span multiple requirements from the profile - may be
> inconvenient or inefficient to test related requirements separately
> 8) The minimum case is a single text document describing the
> convention/profile (cf the NetDCF conventions and DCAT-AP profiles) -
> these still have useful semantics of declaring conformance with the
> profile via a machine-readable identifier.
> 9) SHACL is a potential solution - i dont see a strong requirement for
> it as a specific choice yet
> 
> Please do a sanity check on this reasoning, if you disagree lets discuss
> the specific issue, and if I've missed anything lets capture it. Then
> perhaps review the wording against the constraints, and I will undertake
> to ensure the first-draft of the requirements are properly expressed to
> capture the intent.
> 
> [1] ftp://ftp.unidata.ucar.edu/pub/netcdf/Conventions/README
> 
> On Wed, 23 Aug 2017 at 09:24 Karen Coyle <kcoyle@kcoyle.net
> <mailto:kcoyle@kcoyle.net>> wrote:
> 
>     (Just the description portion)
> 
>     Project X has decided to make its datasets available as open access,
>     downloadable. They do not know who will find the datasets useful but
>     assume that some potential users are outside of Project X's immediate
>     community. They need a way to describe their metadata and its usage such
>     that anyone can work with the datasets, and they hope to do this with a
>     profile that is machine-readable, human-understandable, and that defines
>     the criteria for valid data.
> 
>     Some of their datasets are in RDF and Project X could potentially
>     provide a SHACL document that fulfills the functions above, either
>     instead of or in addition to a profile. However, they also have many
>     datasets that are in metadata schemas for which there is no standard
>     validation language. For those datasets, the profile will need to
>     suffice.
> 
>     Note that there is also a question about the RDF datasets and SHACL. If
>     one expects users of the datasets to be fully conversant in SHACL and to
>     have SHACL tools, then it isn't clear if a profile will provide any
>     additional information to a SHACL validation document. There may,
>     however, be users who wish to work with Project X's RDF data but who are
>     not (yet) using SHACL. There could be both a profile for that RDF data
>     as well as a SHACL document, but the programmers at Project X are wary
>     of having two entirely separate definitions of the data, since it may be
>     difficult to guarantee that they are 100% equivalent.
> 
> 
>     --
>     Karen Coyle
>     kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net
>     m: 1-510-435-8234 (Signal)
>     skype: kcoylenet/+1-510-984-3600 <tel:+1%20510-984-3600>
> 

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234 (Signal)
skype: kcoylenet/+1-510-984-3600

Received on Wednesday, 23 August 2017 03:41:11 UTC