Re: Proof: Linked Data does not require RDF

On 18 June 2013 06:44, David Booth <david@dbooth.org> wrote:

> On 06/17/2013 08:11 PM, Manu Sporny wrote:
>
>> On 06/17/2013 06:21 PM, Luca Matteis wrote:
>>
>>> This still doesn't answer my initial question "How do you produce
>>> Linked Data without RDF?".
>>>
>>
>> Here's the first way (plain 'ol JSON object):
>>
>> {
>>    "id": "http://example.com/people/**luca<http://example.com/people/luca>
>> ",
>>    "type": "http://schema.org/Person",
>>    "name": "Luca Matteis"
>> }
>>
>> The document above is interpreted as Linked Data using the following
>> rules:
>>
>> 1. The thing you're talking about is identified via 'id'.
>> 2. The type of the thing you're talking about is identified via 'type'.
>> 3. All keys, except for 'id' and 'type', are appended to 'type''s value,
>>     with a '/' separator.
>>
>> That's Linked Data. It has no formal relationship to RDF.
>>
>
> No, it is data that is linked.  I would not consider it Linked Data (the
> term of art) because there is no standards-based way to interpret it as
> RDF.  You are using private knowledge to interpret its meaning.
>
> Bear in mind a document does not have to *look* (overtly) like RDF to *be*
> RDF -- i.e., to be standards-based interpretable as RDF.  Arbitrary XML
> documents that use GRDDL are a good example.  If there were a
> standards-based equivalent of GRDDL for the above plain old JSON, then IMO
> it *would* qualify as Linked Data (assuming the URIs are dereferenceable to
> more Linked Data) *because* it could be interpreted via standards as RDF.
>
>
>> Here's the second way (Microdata):
>>
>> http://www.w3.org/TR/**microdata/ <http://www.w3.org/TR/microdata/>
>>
>> The base Microdata spec has nothing to do with RDF. However, if you are
>> going to assert that RDFa is Linked Data, then you have to assert that
>> Microdata is Linked Data. Since Microdata has no linkage to RDF, what
>> are you left with? Answer: A syntax that allows you to express Linked
>> Data without using RDF in any way.
>>
>
> I don't know the status of that spec, but if there is a standards-based
> way to interpret it as RDF, then it qualifies as Linked Data.  If not, it
> doesn't.  It is as simple as that.  (Well, assuming it also makes URIs
> dereferenceable to other Linked Data, etc.)
>

This seems to be turning into a branding discussion.  I think the mug gives
you a good idea of what the brand means:

http://www.cafepress.com/w3c_shop.480759174


>
>
>> Here's the third way (RFC-5988: Web Linking):
>>
>> http://tools.ietf.org/html/**rfc5988 <http://tools.ietf.org/html/rfc5988>
>>
>> The Web Linking RFC defines a typed connection between two resources
>> that are identified by Internationalised Resource Identifiers (IRIs) and
>> is comprised of:
>>
>>     o  A context IRI,
>>     o  a link relation type (Section 4),
>>     o  a target IRI, and
>>     o  optionally, target attributes.
>>
>> Isn't this Linked Data as well?
>>
>
> If it expresses an RDF triple (and if the URIs are dereferenceable to more
> Linked Data), then yes.  Does it?  I'm not sure.  In section 3 I see:
> [[
>    A link can be viewed as a statement of the form "{context IRI} has a
>    {relation type} resource at {target IRI}, which has {target
>    attributes}".
> ]]
> So although that looks somewhat RDF-ish, it is not clear exactly what RDF
> it should represent.  So it looks to me like it is data that is linked, but
> not Linked Data.
>
>
>> Here's a fourth way (HAL - Hypertext Application Language):
>>
>> http://stateless.co/hal_**specification.html<http://stateless.co/hal_specification.html>
>>
>> """
>> HAL provides a set of conventions for expressing hyperlinks to, and
>> embeddedness of, related resources - the rest of a HAL document is just
>> plain old JSON or XML. Instead of using linkless JSON/XML, or spending
>> time developing a custom media type, you can just use HAL and focus on
>> defining and documenting the link relations that direct your clients
>> through your API. HAL is a bit like HTML for machines, in that it is
>> generic and designed to drive many different types of application.
>> """
>>
>> HAL is also Linked Data.
>>
>> To assert that Linked Data requires RDF requires you to make compelling
>> arguments against at least these four pieces of evidence.
>>
>
> They are all data that is linked, but I (and apparently most others in the
> Semantic Web context) would not consider them Linked Data, because IMO
> Linked Data should support the goal of the Semantic Web, and as I explained
> at
> http://lists.w3.org/Archives/**Public/semantic-web/2013Jun/**0120.html<http://lists.w3.org/Archives/Public/semantic-web/2013Jun/0120.html>
> that requires RDF, because RDF is the chosen standard universal
> information model for the Semantic Web.
>
> David
>
>
>