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Re: trusting quads

From: Dan Brickley <danbri@danbri.org>
Date: Wed, 9 May 2012 22:18:51 +0200
Message-ID: <CAFfrAFp+rv0LuPbo9AZi5USLH1CvCLYaFeqmAk4TJHX0zvhzSw@mail.gmail.com>
To: public-rdf-wg@w3.org
On 9 May 2012 22:03, Andy Seaborne <andy.seaborne@epimorphics.com> wrote:
> On 09/05/12 20:02, Sandro Hawke wrote:
>> On Wed, 2012-05-09 at 11:26 -0700, Steve Harris wrote:
>>> Right. The whole reason quads were implemented was to be able to track
>>> what *triples* appears in what documents (typically found on the web,
>>> but file: is good too).
>>
>>
>> Speak for yourself, please, Steve.   I've seen several implementations
>> of quads that were used for other purposes and it's quite possible they
>> predated yours.
>
>
> Which systems?  I'd like to understand the motivations and approaches.

(This dispute feels like unhappy bickering (well, the Steve/Sandro
interaction to name names).)

Triples don't need to be serialized into stable published Web
documents for it to be worth talking about them as a unit; Steve's
'file:' comment acknowledges that, albeit in a serialization-centric
way.

In the FOAF scene 2000-3 we wanted an extra slot for keeping track of
who-said-what, right from the start. Without support for this in basic
RDF tools it was a huge pain to hack at application level, e.g. see
Edd Dumbill's writeup
http://www.ibm.com/developerworks/xml/library/x-rdfprov/index.html

So - yes we wanted extra provenance info. Yes it was usually somehow
associated with a Web document (at some level of abstraction --- could
easily have been in-memory groups of triples too). And yes we wanted
to associate those with other grouping constructs, eg. the human
author.

Steve writes: """You say things like "without taking it as gospel"
because your perspective is of some giant logic system. My perspective
is of databases - I don't "believe" the things in my databases, it's
all about the context. If you ask a user to enter their name, you
don't "believe" the answer they give, you just store it. You can still
query things you don't believe as long as you know the how / why / who
says so. That's what the 4th slot was created for."""

I don't see that as incompatible with a logically-grounded view of
what each bundle of triples is claiming.  At some point, is there some
ground truth, re "as long as you know the how / why / who says so", or
do we also admit possibility of different perspectives (and data
quality, accuracy etc.) on that point?  Perhaps which triples are in
which bundle is ground truth, but which bundle is associated with
which real-world entity ... is something where we allow multiple
perspectives, competing evidence, etc?

Dan
Received on Thursday, 10 May 2012 01:29:18 GMT

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