Re: Sustainable Codes vs Volatile URIs Re: URIs / Ontology for Physical Units and Quantities

Hi Mark

2015-05-07 11:10 GMT+02:00 Mark Harrison <mark.harrison@cantab.net>:

> Dear Bernard,
>
> Just to respond to your example, that is probably an acceptable approach
> provided that both resources sharing that string code do so via a
> well-defined property that has an inverse-functional relationship (i.e.
> only one Subject is allowed to have that Value), much like a social
> security number.


Yes and no :)
Yes for the use of a shared property in a shared stable vocabulary, or even
equivalent properties in separate vocabularies.
But definitely no for the inverse-functional relationship. The weak
semantics of a code implies that it does not commit to any ontological
assumption of whatever the code denotes, and in particular if it denotes a
single entity. In the case of a city code, one can consider the city as a
geographical entity, a surface delimited by a polygon, a minimal and
maximal altitude etc, and another as a populated place with a population at
date X, and yet another one as an administrative subdivision with its
parent territory etc. Those three representations will have different URIs
and different descriptions, and infering they are the same based on an
inverse functional property is likely to entail inconsistent
representations.
The bottom line of this, and I'm aware to be in vehement disagreement with
many people around here, is that a URI does not identify an entity, but a
representation. And a shared code is just a shared key, agnostic on the
ontological status of its referent.


> In that case, it's reasonable to infer that the two resources are the
> same.


Which is leading you dangerously closer to a semantic black hole horizon.


> However, there are several 5-character codes in circulation, whether CAGE
> / NCAGE codes, US 5-digit zip codes or INSEE codes - so it's essential to
> unambiguously specify explicitly what the code represents -


This is simply an impossible task. You share a code, but views on what this
code denotes, implemented as different URIs, can be different. And that
should not be an issue.
If you ask me, the whole semantic enterprise will fail as long as this
point has not been widely understood. I seem to be very abrupt here, but
this is my conclusion after about 15 years munching on those issues, in
theory and in practice ...


> and whether the relationship is inverse functional.  If that is not
> specified in a machine-interpretable manner, we all lose efficiency because
> each responsible developer must verify that relationship manually before
> making that assumption.
>
> The major downside of bare code strings vs URIs is that it's not
> immediately obvious where to go to find information - you can't simply make
> a web request and reasonably hope to find a definition or other
> relationships.  Of course, as Martin points out, we need a stable
> foundation, which for Linked Data means stable URIs and a commitment to
> maintain resources and web vocabularies for the common good, within a
> framework that does not allow them to collapse or wither if one committed
> individual leaves or is run over by a bus.
>
> Best wishes,
>
> - Mark
>
>
> On 7 May 2015, at 09:36, Bernard Vatant <bernard.vatant@mondeca.com>
> wrote:
>
> > Dear all
> >
> > This issue has been surfacing again and again lately, and I would like
> to support Martin. I've already pushed this viewpoint here and there, I
> understand the reaction of "orthodox" linked data supporters for whom
> "things must be identified by URIs", period. But to put in bluntly, in many
> cases, well-maintained codes for standardized identities (languages,
> countries, towns, units ...) are more sustainable ways to share identities
> than URIs, for the obvious reasons given by Martin (URIs are volatile) plus
> three other ones at least.
> >
> > - Codes are not tied to any technical architecture, they can be used and
> exchanged across any information system, not only the Web (semantic or
> not). They allow to "weave beyond the Web" [1] any kind of data using them.
> >
> > - Codes have minimal semantics (if any), they just carry shared
> identities, and that's great. Different data publishers can propose
> different representations, identified by different URIs, and sharing the
> same standard code. The sharing of a code via a common property/value pair
> is the best way to provide loose coupling between those entities without
> engaging into the neverending ontological and technical debate of knowing
> if those representations represent the same/similar/equivalent thing(s),
> and catastrophic chaining triggered by such hazardous equivalences.
> >
> > Let me take just one example. Is not it safer to tie
> http://id.insee.fr/geo/commune/21231 to http://dbpedia.org/resource/Dijon
> by the common value of INSEE code "21231" (standardized by INSEE) than to
> rely on cascading sameAs leading to the stupid semantic black hole at
> > http://sameas.org/html?uri=http%3A%2F%2Fdbpedia.org%2Fresource%2FDijon
> which is the patent proof of the failure of a dogmatic and positivist use
> of URIs.
> >
> > [1] http://bvatant.blogspot.fr/2015/04/weaving-beyond-web.html
> >
> >
> > 2015-05-07 0:31 GMT+02:00 martin.hepp@ebusiness-unibw.org <
> martin.hepp@ebusiness-unibw.org>:
> > The problem is not the one time generation. The problems are as follows:
> >
> > 1. Copyright - Are you allowed to republish the code set as RDF?
> > 2. Sustainability - Are you commited to keep the URIs dereferencable, or
> will some domain grabber take the domain name once the creator has
> completed his/her PhD and lost interest.
> > 3. Updates - Will you keep the RDF version in sync whenever the standard
> changes?
> >
> > Unless there is a clear "yes" to all three questions, it is better to
> use the official codes than derived URIs.
> >
> > Martin
> >
> >
> >
> > > On 06 May 2015, at 23:56, Wes Turner <wes.turner@gmail.com> wrote:
> > >
> > > How much time do you think it would take to generate RDF (and
> namespaced URIs) from the linked spreadsheet?
> > >
> > > Mappings to/from UN/CEFACT codes (as owl:sameAs mappings to strings)
> could certainly be useful.
> > >
> > > On May 6, 2015 4:31 PM, "martin.hepp@ebusiness-unibw.org" <
> martin.hepp@ebusiness-unibw.org> wrote:
> > > I think a validator should simply use the list of valid codes from the
> most recent UN/CEFACT document (available as MS Excel from
> http://www.unece.org/cefact/codesfortrade/codes_index.html).
> > >
> > > There might be unit of measurement ontologies out there that hold the
> UN/CEFACT Common Code string for a subset of all units as a literal value.
> But for validation, one should use the authoritative list from the Excel
> files (since they are updated from time to time).
> > >
> > > URIs are not better than strings for validation, because URIs are
> strings.
> > >
> > > Best wishes / Mit freundlichen Grüßen
> > >
> > > Martin Hepp
> > >
> > > -------------------------------------------------------
> > > martin hepp
> > > e-business & web science research group
> > > universitaet der bundeswehr muenchen
> > >
> > > e-mail:  martin.hepp@unibw.de
> > > phone:   +49-(0)89-6004-4217
> > > fax:     +49-(0)89-6004-4620
> > > www:     http://www.unibw.de/ebusiness/ (group)
> > >          http://www.heppnetz.de/ (personal)
> > > skype:   mfhepp
> > > twitter: mfhepp
> > >
> > > Check out GoodRelations for E-Commerce on the Web of Linked Data!
> > > =================================================================
> > > * Project Main Page: http://purl.org/goodrelations/
> > >
> > >
> > >
> > >
> > > > On 06 May 2015, at 20:34, Wes Turner <wes.turner@gmail.com> wrote:
> > > >
> > > > Thanks!
> > > >
> > > > I notice that with QUDT there are SI conversion factors and complete
> URIs for each unit.
> > > >
> > > > Is there a schema for validation of "schema:QuantativeValues
> supports all UN/CEFACT Common Codes"?
> > > >
> > > > (A similar quandry as with MedicalCode; where URI namespaces (like
> icd10:) would be more helpful for terminological validation and
> disambiguation than plain string keys)
> > > >
> > > > On May 6, 2015 4:26 AM, "martin.hepp@ebusiness-unibw.org" <
> martin.hepp@ebusiness-unibw.org> wrote:
> > > > >
> > > > > Hi Wes,
> > > > > sorry for a very late reply:
> > > > >
> > > > > Actually you could easily use schema:QuantitativeValue for both
> time and volume, with SEC as the unit code for t and LTR as the unit code
> for liters, and link both via schema:valueReference, or better, and
> owl:subProperty thereof.
> > > > >
> > > > > For the principle, see
> > > > >
> > > > >
> http://wiki.goodrelations-vocabulary.org/Documentation/Structured_values_and_value_references
> > > > >
> > > > >
> > > > > schema:QuantativeValues supports all UN/CEFACT Common Codes for
> units, which should cover all you need:
> > > > >
> > > > >
> > > > >
> http://wiki.goodrelations-vocabulary.org/Documentation/UN/CEFACT_Common_Codes
> > > > >
> > > > > (Mind the full list in the public Excel files, the page just
> highlights a small subset.)
> > > > >
> > > > > Best wishes / Mit freundlichen Grüßen
> > > > >
> > > > > Martin Hepp
> > > > >
> > > > > -------------------------------------------------------
> > > > > martin hepp
> > > > > e-business & web science research group
> > > > > universitaet der bundeswehr muenchen
> > > > >
> > > > > e-mail:  martin.hepp@unibw.de
> > > > > phone:   +49-(0)89-6004-4217
> > > > > fax:     +49-(0)89-6004-4620
> > > > > www:     http://www.unibw.de/ebusiness/ (group)
> > > > >          http://www.heppnetz.de/ (personal)
> > > > > skype:   mfhepp
> > > > > twitter: mfhepp
> > > > >
> > > > > Check out GoodRelations for E-Commerce on the Web of Linked Data!
> > > > > =================================================================
> > > > > * Project Main Page: http://purl.org/goodrelations/
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > On 01 May 2015, at 13:45, ☮ elf Pavlik ☮ <
> perpetual-tripper@wwelves.org> wrote:
> > > > > >
> > > > > > Hi Wes,
> > > > > >
> > > > > > On 01/26/2014 07:20 AM, Wes Turner wrote:
> > > > > >> Say I am trying to share a tabular dataset. [1] There's
> metadata for
> > > > > >> the Dataset, and there's metadata for the particular columns
> (which
> > > > > >> applies to the particular data items).
> > > > > >>
> > > > > >> For example:
> > > > > >>
> > > > > >> t   volume (liters)
> > > > > >> -----------------
> > > > > >> 1  1
> > > > > >> 2  0.7
> > > > > >> 3  0.5
> > > > > >> 4  0.3
> > > > > >> 5  0.1
> > > > > >>
> > > > > >> Questions
> > > > > >> ===========
> > > > > >> # Is there (a good) way to specify these units and quantities
> (in
> > > > > >> addition to XSD datatypes)?
> > > > > > You might like to check out
> > > > > > * https://iotdb.org/pub/iot-unit.html
> > > > > >
> > > > > > Cheers!
> > > > > >
> > > > > >
> > > > >
> > >
> >
> >
> >
> >
> >
> > --
> > Bernard Vatant
> > Vocabularies & Data Engineering
> > Tel :  + 33 (0)9 71 48 84 59
> > Skype : bernard.vatant
> > http://google.com/+BernardVatant
> > --------------------------------------------------------
> > Mondeca
> > 35 boulevard de Strasbourg 75010 Paris
> > www.mondeca.com
> > Follow us on Twitter : @mondecanews
> > ----------------------------------------------------------
>
>


-- 

*Bernard Vatant*
Vocabularies & Data Engineering
Tel :  + 33 (0)9 71 48 84 59
Skype : bernard.vatant
http://google.com/+BernardVatant
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www.mondeca.com
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