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Re: Important Question re. WebID Verifiers & Linked Data

From: Melvin Carvalho <melvincarvalho@gmail.com>
Date: Thu, 22 Dec 2011 13:53:10 +0100
Message-ID: <CAKaEYhKpUbGzSWFNHzhXWNs04whMW2xsqhhokRsuMYedoqO8yw@mail.gmail.com>
To: Kingsley Idehen <kidehen@openlinksw.com>
Cc: public-xg-webid@w3.org
On 22 December 2011 13:41, Kingsley Idehen <kidehen@openlinksw.com> wrote:
> On 12/22/11 3:48 AM, Henry Story wrote:
>
>
> On 22 Dec 2011, at 04:42, Kingsley Idehen wrote:
>
> On 12/21/11 3:45 PM, Patrick Logan wrote:
>
> See below...
>
> On Wed, Dec 21, 2011 at 8:27 AM, Henry Story <henry.story@bblfish.net>
> wrote:
>>
>>
>> On 21 Dec 2011, at 14:58, Kingsley Idehen wrote:
>> >
>> > Please understand that RDF != Linked Data. It's just one of the options
>> > for creating and publishing Linked Data.
>>
>> I think it would be very nice to have a formal spec on what Linked Data
>> is. We do have a few for
>> RDF.
>
>
> Yes, please. I understand the RDF-related specifications. And I understand
> the general notion of "linked data". I am someone following the WebID
> effort, and who is contemplating the costs and benefits of supporting it in
> my products at some point.
>
> Unless I see a WebID specification (or a more general "world-wide linked
> data specification") for how to support linked data beyond RDF, how can I
> estimate the costs and benefits of supporting linked data beyond RDF?
>
> Please understand that "publishing and consuming any and all possible
> interpretations of 'linked data'" is probably impossible.
>
> So what are the specific requirements?
>
> -Patrick
>
> Patrick,
>
> Here are the fundamental requirements:
>
> 1. a Data Item (Object or Entity) is uniquely identified by a URI based Name
> 2. use de-referencable URIs as Names that resolve to *descriptor* documents
> (resources) that describe the URI's referent
> 3. descriptor documents (resources) should *consist* or *bear* structured
> data in the form of eav/spo triples (or 3-tuples) statements that
> collectively form a directed graph pictorial that coalesces around the
> description subject's URI .
>
> You can make statements eav/spo statements using a variety of syntaxes.
> You can serialize eav/spo bearing resources across the wire using a variety
> of data serialization formats.
> You can leverage HTTP as a low cost and effective mechanism for:
>
> 1. de-referencable URI based Names
> 2. negotiation of data serialization formats between servers and clients
> (user agents).
>
> The WebID spec can require or suggest a number of common formats for eav/spo
> triple transmission as the basis for effective bootstrap.
> The WebID spec should never (overtly or covertly) be a tool for fighting or
> prolonging  syntax of format wars re. eav/spo triples.
> The WebID spec should never leak the abstraction inherent in URIs by
> mandating http: scheme URIs.
> The WebID spec should never compromise the fidelity of Linked Data by
> favoring a particular style of de-referencable URI.
> The WebID spec is a spec. It shouldn't attempt to teaching software
> engineering.
>
> All of the above is possible without adversely affecting WebID. In short,
> all of this will make WebID attractive to much broader developer profiles
> that extend beyond the RDF based Semantic Web community.
>
> What's the difference between RDF and EAV?
>
> RDF explicitly (via spec) requires the use of URIs in S, P, and O
> (optionally) slots of triple statements. It also handles typed literals and
> language tags. Basically, it caters for locale issues and i18n.
>
>
> In fact RDF semantics does not do this. It is just the RDF serialisations
> that do, and for not such bad reasons. RDF semantics allows numbers in
> predicate positions, though these don't have much use there. There is even
> an example in the spec about this here http://www.w3.org/TR/rdf-mt/ !
>
>
> Put differently, RDF introduces (as part of its spec) URIs to EAV. That's
> the fundamental point.
>
>
> You can map every EAV to SPO, and can in fact infer from each. SPO is much
> cleaner theoretically than EAV as it is purely relational, and everything
> can be mapped down to relations in the end.
>
>
> S-P-O and E-A-V are 3-tuples with different letters. The use of URIs is
> where RDF starts to be more specific. The aforementioned specificity extends
> to typed literals, language tags, and i18n.
>
>
> So really all that Kinglsey is doing is change the language because he
> thinks that it is the language that was the problem with RDF, where in
> fact I think there were quite a number of other issues that were the
> problem, such as no decent tooling and no understanding from the developers
> of even REST at the time. XML had just came out and it promised to do
> everything, which shows just how syntactically people were thinking at the
> time.
>
>
> No, since I know myself pretty well, here is what I am doing:
>
> I am trying to make the issue of Linked Data (foundation layer of the
> Semantic Web Project) more accommodating. Achieving this accommodation means
> introducing missing genealogy to the RDF narrative.
>
>
>
> In the mean time Java came out and .net and the idea that multiple languages
> could be used to program to the same machine. That the machine itself could
> be virtual. And so the notion of semantics is very widely spread in the
> procedural space.
>
>
> Please!
>
> Semantics has been in computer science since forever. RDF isn't the
> progenitor!
>
>
>
>  So in my view this is the wrong time to shift.
>
>
> The fact that you think I am seeking a shift is symptomatic of the
> fundamental issue we are having re. communications. Put differently, your
> arguments right now are exactly the same as the arguments you were
> attempting to make about slash vs hash URIs yesterday. Eventually, you found
> out that it was down to a bug.  Please re-read yesterday's thread. Until you
> found the bug you were making a contradictory argument. You are repeating it
> again (albeit different context) right now.
>
>
> It is as if you had asked people about Object Oriented programming in 1992.
> There would have been huge arguments about its complexity (c++) or
> academicity (eifel, ...), then Java come out and 5 years later you could not
> program without doing OO.
>
>
> The problem with OO languages is that Object Theory isn't a programming
> language specific thing. Linked Data is about unshackling Object Theory from
> programming languages.
>
> Data Objects can exist independent of any programming language, operating
> system, or dbms engine specificity. When all is said and done, this is what
> AWWW is delivering to the world, the final unshackling of Data from Code.
>
>
> OWL is just OO for relations btw.
>
>
> OWL is about Semantic Fidelity for relations. These relations take the form
> of eav/spo 3-tuples (triples).
>
>
>
>
> EAV isn't as specific as RDF with regards to the items above. At the same
> time EAV is well known, and doesn't carry the political baggage of RDF.
>
>
> I am not sure there is a Political baggage of RDF.
>
>
> We view the world through completely different "context lenses". I know the
> letters R-D-F carry huge political baggage that continues to impede
> comprehension and adoption of the Semantic Web vision.
>
> I can separate concepts for syntaxes (programming language or markup) . You
> claim you can, but you are always talking about parsers. I don't think about
> parsers when working on WebID, Linked Data etc.. I think about: data
> objects, locations/addresses, negotiable representation, relations, and the
> semantic fidelity of relations.
>
> All linked data does RDF and it is growing very fast. People are
> understanding that RDF is about semantics and relations. and I get very
> little negative feedback about RDF. Even Facebook is publishing Turtle now!
>
>
> Again, here is where you are incorrect. Facebook is publishing Linked Data
> and that has zilch to do with Turtle, which is just another syntax for
> expressing eav/spo based triples as well as being yet another
> across-the-wire serialization format. When Facebook officially decided to go
> with Linked Data I wrote a note [1] deconstructing what they did, I
> encourage you to read it.
>
>
>
>
> What's the difference between RDF and Linked Data?
> There is nothing in the RDF spec (even as I write) that specifies the
> behavior of URIs used in SPO triples. For instance RDF doesn't explicitly
> distinguish between a URI that serves as a Name and a URI that serves as a
> Resource Locator (Address).
>
>
> And that is very good. RDF is about semantics and logics. Linked Data is
> pattern of publication of this data. Linked Data still has to be fully
> specified by the W3C, but it is obviously exactly how Tim Berners Lee
> intended RDF to be used.
>
>
> TimBL did not intend for any specific syntax. He had a clear vision for
> InterWeb scale Linked Data. RDF happened to be a vehicle for vision
> manifestation.
>
> You are still failing to accept that RDF isn't the progenitor.
>
> This was not understood by the RDF logicians he employed necessarily because
> they had a different background.
>
>
> Linked Data is very specific about URI behavior. It expects URI based Names
> and Addresses to be distinct.  This is why it's always problematic to infer
> (overtly or covertly) that RDF == Linked Data. The *truth* of the matter is
> that RDF is one approach to constructing directed graph based descriptor
> resources (comprised of eav/spo triples) that result in Linked Data at
> various scales (local area network or wide area network e.g., the InterWeb).
>
>
> RDF is mathematically defined, therefore it covers all ways of doing
> relational stuff. you can of course re-invent it, but then it would take no
> time to map that back to rdf, so your time would be wasted.
>
>
> Again, you are making a comment short on deeper information. If you want to
> understand what's going on with relations and data I suggest you digest an
> article I stumbled across recently titled: A co-Relational Model of Data for
> Large Shared Data Banks [2].
>
>
> I will therefore continue speaking in terms of RDF and Linked Data.
>
>
> You can speak in terms of RDF and Linked Data. Just don't try to infer that
> RDF is the only option for producing Linked Data since that's an utter
> fallacy. Also, don't claim WebID is about Linked Data if it doesn't support
> Linked Data principles. Again, remember, you found a bug yesterday in your
> code. Prior to finding a bug in your verifier, you were heading down a very
> slippery slope re. your arguments about why Linked Data clients should be
> discriminating against a particular style of de-referencable URI.
>
> Those are clearly understood, extremely well specced out, and there is now
> 12 years of accumulated knowledge in that space. We  also have the tools to
> do things there.
>
>
> I am no stranger to RDF tools.
>
>  Plus we are at the W3C here and we can use the vocabulary. NASA uses RDF,
> governments use RDF, companies are using them, social networks are using it.
> All in more and more linked data manners.
>
>
> Any you feel you need to educate me about who is using RDF to do real work
> across industry?
>
>
> Perhaps some crowds need to be talked to in terms of EAV, but we are not
> going to write a spec in latin to make the vatican happy too either.
>
>
> I haven't asked you to put EAV into the WebID spec. I've asked you to make
> up your mind about WebID re., the following:
>
> 1. Linked Data
> 2. Architecture of the World Wide Web.
>
> Yesterday, you were basically "walking the plank" on both fronts. Now you've
> fixed the bugs in your service, and we just might be back on track re. the
> suggestions you make. Please remember, this thread is about WebID Verifiers
> and Linked Data (which is an application of AWWW). Yesterday, you made
> contradictory suggestions re:
>
> 1. URIs  -- slash or hash based HTTP scheme URIs
> 2. HTTP -- re. 303 redirection.

I think everyone is agreed to that WebID should conform to web arch.

Most of what I know about web arch I learnt from:

http://www.w3.org/DesignIssues/

Every article there is pure gold, particularly the axioms/principles.
Yet almost no one reads them! :)

My understanding is if WebID (as a web arch conformant authentication
protocol) is committed to web arch, it has to pass the law of
independent invention, which probably means it has to to be linked
data compatible.

I think the debate here is whether we are almost there (Kinsley) or
100% there (Henry).

Either way I think it's only a few tweaks (allbeit extremely important
ones), which is part of what the XG is there to find out.

So I think we're all agreed WebID wants to conform to web arch, in
spirit and in spec.

So what are the practical implications, if any (perhaps something to
be fleshed out in another thread)

>
> Links:
>
> 1. https://plus.google.com/112399767740508618350/posts/6cqa1Sxk5KV -- What
> Facebook Can Teach Us about Bootstrapping Linked Data at InterWeb Scales
> 2. http://queue.acm.org/detail.cfm?id=1961297 -- A co-Relational Model of
> Data for Large Shared Data Banks .
>
> Kingsley
>
>
> Henry
>
> Regards,
>
> Kingsley Idehen	
> Founder & CEO
> OpenLink Software
> Company Web: http://www.openlinksw.com
> Personal Weblog: http://www.openlinksw.com/blog/~kidehen
> Twitter/Identi.ca handle: @kidehen
> Google+ Profile: https://plus.google.com/112399767740508618350/about
> LinkedIn Profile: http://www.linkedin.com/in/kidehen
>
>
>
>
>
> Social Web Architect
> http://bblfish.net/
>
>
>
> --
>
> Regards,
>
> Kingsley Idehen	
> Founder & CEO
> OpenLink Software
> Company Web: http://www.openlinksw.com
> Personal Weblog: http://www.openlinksw.com/blog/~kidehen
> Twitter/Identi.ca handle: @kidehen
> Google+ Profile: https://plus.google.com/112399767740508618350/about
> LinkedIn Profile: http://www.linkedin.com/in/kidehen
>
>
>
>
Received on Thursday, 22 December 2011 12:53:48 GMT

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