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Re: Requirements for profiles

From: Karen Coyle <kcoyle@kcoyle.net>
Date: Fri, 17 Nov 2017 12:29:28 -0800
To: Rob Atkinson <robatkinson101@gmail.com>
Cc: Ruben Verborgh <Ruben.Verborgh@ugent.be>, public-dxwg-wg@w3.org
Message-ID: <6070ce0d-de83-d679-e2a6-4ef8d81b93e7@kcoyle.net>
This would require some rules about equivalence, assuming that profiles
include definition details such as cardinality of properties (0...n vs.
1,1), dependencies (foaf:name or [foaf:forename, foaf:familyname]), and
value rules (foaf:familyname must be "Smith" or "Jones") (foaf:name is a
maximum of 32 characters).

This is why we need to consider this interest in inter-changeability
along with the desire for detail. The more detail provided, the less
interchangeable profile definitions tend to be. If less detail is
provided, then the informational value of profiles is lessened.

That said, and picking up on some of the work taking place with SHACL
and ShEx, it may be desirable to have some canonical representations of
very common properties that can be used in various situations. This then
butts up against the cautions that Annette voiced: how volatile a
situation can you tolerate for a data profile?

We still need a requirement that we can agree on to cover this case, if
Rob or Ruben would like to work on that.


On 11/17/17 11:27 AM, Rob Atkinson wrote:
> Agree fully with Ruben here, and also Karen is right that combinations
> may be tricky.. but that is indeed a strong argument for a rich
> canonical representation of profile constraints, and strong identity
> governance, so common constraints can be unambiguously recognized by
> implementations that do not need to be sophisticated enough to read and
> combine these constraint fragments that define the behavior of the resource.
> DCAT cant be the description vocabulary imho, but it can define profile
> identity and declaration of conformance mechanisms,  and the semantics
> of combinations of conformance declarations.
> Rob
> On 18 Nov 2017 3:55 AM, "Karen Coyle" <kcoyle@kcoyle.net
> <mailto:kcoyle@kcoyle.net>> wrote:
>     On 11/17/17 7:30 AM, Ruben Verborgh wrote:
>     > Hi Karen,
>     >
>     >> Not sure what you mean by "composed."
>     >
>     > Maybe I should have just said "combination",
>     > but I meant using multiple profiles in conjunction.
>     > Example:
>     > – Profile A: "use FOAF to describe people"
>     > – Profile B: "use Schema.org to describe books"
>     >
>     > When a representation does both of the above,
>     > then it conforms to both profiles
>     > and we essentially have a composition of profiles A and B.
>     Ruben, I think this is a variant view of profiles, so we should discuss
>     it as a group. The APs that exist today for DCAT are complete
>     descriptions of all of the elements of a metadata schema. As I read them
>     they cannot be combined as they are, nor can parts or fragments be
>     combined as new profiles because they haven't been designed to be
>     uniformly combinable. That is an interesting interpretation but not one
>     that we have yet as a requirement.
>     Your use case appears to assume profiles that each conform to a single
>     entity description, in one case people in the other case books. However,
>     a "book" description (as I show here [1] and that is the case for real
>     book metadata [2]) includes everything needed to describe a book
>     including information about the people who write them.
>     If you have profiles that, for example, are metadata descriptions for
>     books, and they have these characteristics:
>     1 - FOAF for people, BIBO for books
>     2 - BIBFRAME for people, schema.org <http://schema.org> for books
>     it seems to me unlikely that any combination of them would be workable.
>     At the same time, having a way to create profiles as "fragments" that
>     can be combined is an interesting idea, so we should explore that.
>     kc
>     [1] http://dublincore.org/documents/profile-guidelines/
>     <http://dublincore.org/documents/profile-guidelines/>
>     [2] http://www.loc.gov/bibframe/docs/index.html
>     <http://www.loc.gov/bibframe/docs/index.html>
>     >
>     >> conformance to multiple profiles is a function of
>     >> the service that is determining "conformance". The profiles are
>     >> essentially inert in that process - they are being acted on.
>     >
>     > Conformance isn't necessarily determined afterwards by a service.
>     > A server could also just directly generate a conforming
>     representation.
>     >
>     > I'd say that the profile itself defines with conformance means,
>     > regardless of the way to validate it.
>     >
>     >> What isn't clear to me is the "response" part. What is doing the
>     >> responding? or what is the nature of this thing called "response"?
>     >
>     > This is in the context of an HTTP request and response.
>     > A client sends an HTTP request to receive a representation of a
>     resource.
>     > The server responds with that representation.
>     >
>     > So given a dataset, the server will respond with a representation
>     > of that dataset that conforms to zero or more profiles.
>     >
>     > Best,
>     >
>     > Ruben
>     >
>     --
>     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:%2B1-510-984-3600>

Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234 (Signal)
skype: kcoylenet/+1-510-984-3600
Received on Friday, 17 November 2017 20:29:54 UTC

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