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RE: remove hydra:Resource and hydra:Class

From: McBennett, Pat <McBennettP@DNB.com>
Date: Mon, 12 Jan 2015 04:03:56 -0600
To: Dietrich Schulten <ds@escalon.de>, "public-hydra@w3.org" <public-hydra@w3.org>
Message-ID: <52EE3F4A5E7F194A963FE14B2DDBDBFE3BDC9C9D2C@DNBEXCH01.dnbint.net>
Just my 2cents, but this issue has bugged me for a long time now (and not just in Hydra). The argument for keeping Hydra completely self-contained, and therefore the only vocab a new user needs to see or understand is laudable, but I think a better balance can be struck between that and gently introducing new users to the huge benefits of reusing existing well-known vocabularies. So couldn't we reuse really basic and simple existing vocabs, ones that won't scare off, overly burden or confuse new users?

I'd certainly agree that 'owl' is way too much, but I think reusing existing terms from Schema.org, RDFS and possibly Dublin Core would strike a perfectly reasonable balance here (NOTE: I don't think the RDF vocab should be used, as it's terms only refer to the mechanics of RDF, i.e. confusing things like 'subject', 'predicate', and 'Statement').

But for instance, RDFS only has 15 terms (so not daunting in terms of size), and it includes really useful terms like 'label', 'comment', 'seeAlso', 'domain', 'range' and 'member'. I don't think a new user needs to live in the RDF universe to grasp what those terms mean. The same applies for Dublin Core I think, and certainly for Schema.org (although their particular use of 'title' seems tied to job postings [1]!).

I know we can map things like 'hydra:title' to 'dc:title' or 'rdfs:label' for the RDF-savvy audience, but I honestly think the cost to new users of needing to be aware of a vocab as simple as RDFS is worth it in terms of reducing the footprint of Hydra itself, while also demonstrating the power of Linked Data by Hydra itself actually reusing existing vocabs (and it removes any need for inference or 'owl:sameAs' overhead for the RDF guys).

I don't think that represents radical pureness, does it...?

Cheers,

Pat.

[1] - http://schema.org/title


From: Dietrich Schulten [mailto:ds@escalon.de]
Sent: 12 January 2015 08:58
To: public-hydra@w3.org
Subject: Re: remove hydra:Resource and hydra:Class

and hydra:description. But you see where this is heading. People will have to learn about owl and rdfs before they can use hydra for their restful services. This is assuming that hydra is not only for people who live in the rdf universe.

For practical reasons and to ease adoption it is a good thing if it is sufficient to learn about one vocabulary that covers the semantics of a ReST Service, and domain-specific vocabularies on the other hand.
Having one vocab also makes it quite easy to define a set of semantics a hydra-conformant client must, should and may support. Sure, I can say anything about any resource, but I cannot expect that the hydra client will understand everything I say.

At this point I do not think we should try to express as much as possible in pure rdfs and owl in the :ApiDocumentation and the resources themselves. Rather we need a "complete" set of semantics a hydra client can be expected to understand. The lithmus test for completeness: if a property or class may be useful for a restful service, it should be in hydra.

We must certainly strike a balance here. But the radical pureness seems not right to me.

Best regards,
Dietrich
Am 11.01.2015 um 22:34 schrieb Thomas Hoppe:
maybe also hydra:title

:-)
On 01/11/2015 10:18 PM, Ruben Verborgh wrote:

Following this train of thought one would also have to question the added value of the hydra:Link class instead of using rdf:Property or owl:ObjectProperty.

Fair enough. As far as I'm concerned: to be discussed next :-)



Ruben
Received on Monday, 12 January 2015 10:04:28 UTC

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