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Re: Ending the Linked Data debate -- PLEASE VOTE *NOW*!

From: David Booth <david@dbooth.org>
Date: Fri, 14 Jun 2013 00:53:49 -0400
Message-ID: <51BAA1DD.20108@dbooth.org>
To: Manu Sporny <msporny@digitalbazaar.com>
CC: public-lod@w3.org
Hi Manu,

On 06/13/2013 03:50 PM, Manu Sporny wrote:
> bcc: RDF WG
>
> *JSON-LD Chair hat on*
>
> David Booth wrote:
>> In normal usage within the Semantic Web community, does the term
>> "Linked Data" imply the use of RDF?
>
> David,
>
> I really wish you would have passed this poll by both the JSON-LD group
> and the RDF WG before sending it out so that we could have settled on
> the set of right questions to ask.

And spent even *more* time arguing over the wording of the poll?   I 
thought that would be a bad idea.

But other polls can certainly be developed, and I would encourage others 
to do so if they wish.  If we get enough answers from them, the results 
could be very illuminating in understanding the different perspectives 
in different communities.

> As others have pointed out, you're
> phrasing the question in such a way as to ignore the point of
> contention.

Apparently we have vastly different ideas of what that point of 
contention is.

> This is only going to muddy the already opaque waters.

I do not see how quantitative data on the meaning of a term could 
possibly muddy the waters.

>
> Additionally, I don't see what marginalizing other Linked Data
> technologies (that are "not RDF") is going to accomplish.

I have to object to that statement, because the phrase 'other Linked 
Data technologies (that are "not RDF")' already implies that Linked Data 
is *not* necessarily based on RDF, whereas that is the question that 
this debate is trying to resolve!

>
> To the rest of the members of these mailing lists,
>
> A number of us have been having an off-list exchange over why the text
> outlining Linked Data is what it is in the JSON-LD spec. I'm going to
> share parts of that exchange (only the bits that I wrote, names
> redacted) in order to shine some light on why David Booth is trying to
> get feedback from this community.
>
> ------------------
>
>>> [Assertion that Linked Data implies the use of RDF]
>
> Manu Sporny wrote:
>> I know that you think it [Linked Data] has a well-established meaning
>> in "the community". I disagree, not because I necessarily care that
>> deeply about it, but because when we asked "the community" for the
>> definition, we received a myriad of different answers from people
>> that have been core to the process over the last decade. This led to
>> a huge amount of work for the group because of exactly the type of
>> exchange that is happening between [XXX] and [YYY]. [The definition
>> of Linked Data] may seem clear to each of you, but I can assure you
>> that it's not at all clear to the rest of us.

Hopefully this poll will shed some quantitative light on what this term 
means **within the Semantic Web community.**  It will not answer the 
question of what the term means to those outside of that community who 
have little or no knowledge of the term's origin.

>>
>> Both of you are arguing over what each of you think was in TimBL's
>> head at the time. We can't base anything off of such a line of
>> argumentation.

The argument has been approached from multiple angles: assertions about 
what the term currently means, evidence about what it currently means, 
evidence about what TimBL coined it to mean, and contextual 
recollections about what was going on at the time.  the assertions about 
what the term currently means are likely to go nowhere without 
quantifiable evidence. that's why I made that poll.  other less direct 
evidence of what the term currently means -- looking at the top 10 hits 
of the three most obvious Google searches of the term's meaning -- did 
not seem to have any affect on those who had already made up their 
minds.  (perhaps they never looked at them?)

Honestly, the problem seems to be that there are some loud voices that 
are not even *looking* at the evidence, regardless of how convincing 
that evidence may be.

case in point: I have been repeatedly been accused of equating Linked 
Data with RDF, which is patently untrue.  Regardless of how many times I 
have pointed out that I have *never* equated Linked Data with RDF -- 
that Linked Data is RDF but RDF is not necessarily Linked Data -- it 
seems to have no effect, which is quite frustrating.

another case in point: I have multiple times seen the assertion that 
TimBL's original Linked Data document did not mention RDF, in spite of 
the fact that anyone who takes the time to actually *read* that document 
can plainly see that it *explicitly* mentions RDF:
http://web.archive.org/web/20061115043657/http://www.w3.org/DesignIssues/LinkedData.html
this certainly makes it appear as though some voices in this argument 
would rather stick to their opinions than look at the actual evidence, 
which is rather discouraging in a technical forum.

>>
>> We debated the normative definition of Linked Data for months during
>>   the development of JSON-LD. We even came up with normative spec text
>>   so we could define what Linked Data is once and for all. We were
>> then asked to remove the definition from the spec by the RDF WG
>> because "it may be used to exclude certain technologies as Linked
>> Data and further fracture the Linked Data movement." Damned if you
>> do, damned if you don't.
>>
>> You can read the logs here, if you'd like:
>>
>> http://json-ld.org/minutes/2011-07-04/
>> http://json-ld.org/minutes/2011-07-26/
>>
>> You can see the start of the normative definition of Linked Data
>> here:
>>
>> http://json-ld.org/requirements/ED/20110703/#linked-data
>>
>> We did this because there was, and continues to be, no normative
>> definition of Linked Data.
>>
>> You are going to get a fantastic amount of push-back if you claim
>> anything to the contrary on the call. I'd re-think your approach if
>> I were you and base a line of argumentation on why "RDF" should be
>> mentioned on first principles rather than relying on something TimBL
>> wrote over a decade ago.

He wrote that Linked Data document in 2006 -- not over a decade ago.  I 
am not basing my argument on that document.  I am basing it on the 
established meaning of the term within the Semantic Web community and on 
the importance of the term to the Semantic Web community.  That document 
only provide evidence of the term's original meaning within the Semantic 
Web community.  It does not provide quantitative evidence of the term's 
current meaning within the Semantic Web community.

>
>>> [Assertion that the JSON-LD group is deliberately misleading the
>>> public by not asserting that Linked Data implies the use of RDF]
>
> Manu Sporny wrote:
>> I can't speak for the others, but I'm not convinced that we should
>> change it at this point because your line of argumentation has been
>> unconvincing. All that has happened to date is that both you and
>> [YYY] have provided evidence that there exist versions of TimBL's
>> document that do include RDF and don't include RDF when the concept
>> of Linked Data was introduced.

Again, that is factually incorrect.  I implore you to *please* read that 
document:
http://web.archive.org/web/20061115043657/http://www.w3.org/DesignIssues/LinkedData.html
Don't take my word for it -- just read it.  It very clearly *does* say 
RDF.  It does not say RDF in *every* sentence, because RDF was the 
context.  But notice the very first sentence.  And notice the full 
paragraph that explains rule three of "The four rules":

[[
The third rule, that one should serve information on the web against a 
URI, is, in 2006, well followed for most ontologies, but, for some 
reason, not for some major datasets.  One can,  in general,  look up the 
properties and classes one finds in data, and get information from the 
RDF, RDFS, and OWL ontologies including the relationships between the 
terms in the ontology.
]]

Notice that it says "*the* RDF, RDFS, and OWL ontologies.

Again, it is quite frustrating to repeatedly read verifiably false 
statements about that document, when the document is right there for 
anyone to read.

>>
>> Additionally, you haven't countered these pieces of evidence at all:
>>
>> http://www.w3.org/DesignIssues/diagrams/history/proposal-fig1.gif

Wow.  I am baffled at why you think that needs to be "countered".  That 
is an illustration from TimBL's original proposal for the web.  It 
pre-dated TimBL's coining of the term "Linked Data" by over a decade!  I 
have no idea why anyone would think it is relevant to the definition of 
Linked Data.

>> http://www.w3.org/2005/Talks/1110-iswc-tbl/#(4)
>> http://www.w3.org/2005/Talks/1110-iswc-tbl/#(7)

Those slides also pre-dated TimBL's coining of the term by nearly a 
year.  Again, I have no idea why anyone would think they are relevant to 
the definition of Linked Data.

>> http://dig.csail.mit.edu/2007/Talks/0511-tab-tbl/#(10)

That presentation is about Tabulator, which is an *RDF* browser!  The 
fact that slide 10 did not mention RDF should not be surprising, because 
the *entire* slide set is about RDF!  (Take a look!)

>>
>> Similarly, [YYY] hasn't countered yours. It's impossible to do so.
>> Neither one of you are going to be successful in convincing the other
>> about what was going on in TimBL's head. So, we're just stuck here
>> watching [XXX] and [YYY]'s conversation devolve to the following on a
>> public mailing list:
>>
>> Yeah-huh! Nuh-uh! Yeah-huh!!! Nuh-uh!!!
>>
>> You need some new, convincing evidence.

That is exactly what I am trying to obtain by putting out this poll.

>> Additionally, even if that
>> evidence is TimBL himself stating that Linked Data is based on RDF,
>> you should prepare yourself for people to disagree vehemently with
>> that assertion as there are research papers that stretch all the way
>> back into the late 1970s covering things that pass the duck test as
>> Linked Data:
>>
>> 1976 - Peter Chen's thesis on "Linked Data"
>> http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.123.1085&amp;rep=rep1&amp;type=pdf

What????  How could a 1976 paper that never uses the term "Linked Data" 
possibly have any bearing at all on the current meaning of the term 
within the Semantic Web community?

This argument is not about whether there exists data that is linked 
without using RDF, nor is it about whether such concepts existed before 
TimBL coined the term "Linked Data".   This argument is about what this 
term now means -- as a term of art -- within the Semantic Web community.

>
>>> [[YYY] has misled the community into thinking that Linked Data
>>> does not necessarily imply RDF.]
>
> Manu Sporny wrote:
>> What convinced me were facts and a sound line of reasoning. You are
>> assuming that the people that work on JSON-LD are easily swayed. You
>> have used facts, but have not provided a sound line of reasoning for
>> why we should state that Linked Data is RDF or is based on RDF.

I don't understand what you mean.  If facts are not enough, what kind of 
line of reasoning do you want?

>
> The very next e-mail I saw was the one calling for a poll on this matter.
>
> The point of contention isn't about what the Semantic Web community
> thinks about the definition of Linked Data.

Apparently we have very different views about what is the point of 
contention here, since to my mind that is *exactly* the point of 
contention.

> The point of contention is
> if a large majority (90%+) thinks that Linked Data requires/implies the
> use of RDF.

Majority of what population?  It would be pointless to ask a general 
population, since we are talking about a particular term of art.  if you 
dilute the population with those who do not know what the term means, or 
who *think* that they know what it means, based on its generic 
descriptive meaning rather than its special meaning as a term of art, 
then you get a distorted and misleading answer.

>
> In order to discover the answer to that question, we would need an array
> of questions posed to the general Web community that ask the following:

The general Web community???  That would be like asking the general 
population to define the medical term "acute care".  (Most of the 
population thinks that term refers to treatment for a severe medical 
condition.  But it doesn't.  It means short term medical care.)

Asking the general Web community will shed no light whatsoever on the 
special meaning of "Linked Data" as a term of art in the Semantic Web 
community.

>
> 1. Does the use of Linked Data imply the use of RDF?

"Of course not.  My database tables are linked, and they don't use RDF. 
  What is RDF anyway?  Isn't that like an electronic barcode or something?"

>
> 2. Does the use of Linked Data require the use of RDF?
>
> 3. Do you need to utilize many of the RDF Concepts to publish Linked
> Data, or are simple key-value pair objects that use URLs to refer to one
> another enough? That is, if JSON-LD didn't map to RDF at all, would it
> still be considered Linked Data?
>
> 4. Must the definition of Linked Data make it explicit that Linked Data
> is based on RDF?
>
> 5. Is there an EAV model that is not the RDF model but could be used to
> express Linked Data?
>
> 6. Can vanilla JSON express Linked Data?
>
> We can't address this question without being nuanced, because the
> nuances matter. We can't focus the questions on just the Semantic Web
> community. We need to cast a wider net and bring in Web developers with
> no real background in formal logic and semantics.
>
> We already went through this process before and whittled the definition
> of Linked Data down to something that achieved consensus, and stood
> untouched for a long time:
>
> http://www.w3.org/TR/json-ld/#introduction
>
> Going around the group, re-raising the question while submitting no new
> evidence, especially after all of the evidence was laid out plainly, is
> bad form.

There was no attempt to go around the group.  This was an attempt to 
efficiently add some objective, quantitative evidence to the debate -- 
pure and simple -- to reduce the subjective back-and-forth arguments.

>
> That said, if you would like to work with the JSON-LD and RDF groups to
> formulate a questionnaire that meets the needs of both sides of this
> debate, I urge you to do that (and not circulate polls that only have
> one correct answer).

We could, and I would be happy to help, but it sounds like we so far 
pretty far apart about what questions should be, so it may take some 
work to figure that out.

BTW, lest anyone gets the wrong impression of where this discussion is 
going, I would like to quote from another private message in the 
exchange that Manu mentioned.  This one was from me:
[[
I think everyone's intentions are in the right place -- including 
Kingsley's --  but in some cases I think zeal overstepped accuracy. 
Fortunately, I think we are on a good path to correct those oversteps 
while still being developer-friendly.  I personally appreciate the 
group's willingness to work directly with members of the community to 
resolve these issues fairly.
]]

That still reflects my overall view.

Thanks,
David
Received on Friday, 14 June 2013 04:54:18 UTC

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