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Re: Clarification required: BP6 "use HTTP URIs for spatial things"

From: Krzysztof Janowicz <janowicz@ucsb.edu>
Date: Thu, 1 Sep 2016 14:42:46 -0700
To: Joshua Lieberman <jlieberman@tumblingwalls.com>, Jeremy Tandy <jeremy.tandy@gmail.com>
Cc: Frans Knibbe <frans.knibbe@geodan.nl>, SDW WG Public List <public-sdw-wg@w3.org>
Message-ID: <1190e136-6e0e-cb97-3c13-93b3e17411cc@ucsb.edu>

Hi,

> So as representations, these are not “owl:sameAs”.


Just for clarification. owl:sameAs is only concerned with the mapping of 
IRIs to (real world) entities and not 'representations' (leaving aside 
the fact that everything is a representation in some sense). I.e., it is 
about 'identity'. To give an extreme example, a URI may refer to the 
Eddystone Lighthouse which may be classified as /Lighthouse/ in some 
repository. Another URI established 50 years from now can still refer to 
this particular (4th) lighthouse and classify it as a /Ruin/. Another 50 
years into the future, there may be yet another URI that refers to the 
fact that at some stage there was a ruin here of the 4th lighthouse 
called Eddystone while there is nothing physical left of it, and, thus, 
it is neither classified as /Ruin/ nor /Lighthouse/. In fact, we do not 
even need to introduce the concept of "real world" here as we can also 
establish a sameAs relation between two URIs that point to Zeus. Please 
note that this is different from establish a sameAs link between a 
particular statue of Zeus in a particular museum and Zeus as the god of 
thunder. Finally, the purpose of establishing sameAs links is typically 
data fusion/conflation (no matter whether this is done ad-hoc, manually, 
or (offline) computationally) .

Best,
Jano


On 08/31/2016 06:38 AM, Joshua Lieberman wrote:
> Jeremy,
>
> So as representations, these are not “owl:sameAs”. We assume that as 
> feature data, each refers to a real world entity, but we don’t assert 
> that this VerticalObstruction is the same individual as this 
> MaritimeNavigationAid. We just are suspecting or asserting that the 
> same real world thing is being discerned in two different ways. 
> Someone may define a lighthouse class as subclassing both, otherwise a 
> slightly specialized relation (e.g. sdwgeo:sameRealWorldEntityAs) 
> would be useful here.
>
> Josh
>
>> On Aug 31, 2016, at 8:41 AM, Jeremy Tandy <jeremy.tandy@gmail.com 
>> <mailto:jeremy.tandy@gmail.com>> wrote:
>>
>> > That still leaves a gap in expressing whether two feature data 
>> entities represent the same real world entity.Perhaps we need a 
>> "sameFeatureAs" predicate to address this.
>>
>> @josh - can we clarify my understanding please?
>>
>> In the BP doc §4 "Spatial things, features and geometry" [1] I use a 
>> lighthouse example, so I'll continue with that ...
>>
>> We have one real lighthouse (Eddystone Lighthouse) that is discerned 
>> as a different Type by different communities: "VerticalObstruction" 
>> and "MaritimeNavigationAid". In ISO 19100 parlance, these are two 
>> distinct feature types. The two "Features" might be encoded in GML as 
>> follows (forgive any errors in my illustrative example):
>>
>> <VerticalObstruction gml:id="a">
>> <gml:name>Eddystone</gml:name>
>>     <gml:identifier 
>> codeSpace="http://example.com/sar/features/vo/">EDY</gml:identifier 
>> <http://example.com/sar/features/vo/%22%3EEDY%3C/gml:identifier>>
>>     <geometry>
>>         <gml:Point gml:id="a-p1" srsDimension="2" srsName="EPSG:4326">
>>             <gml:pos>50.184 -4.268</gml:pos>
>>         </gml:Point>
>>     </geometry>
>>     <height uom="m">41</height>
>> </VerticalObstruction>
>>
>> <MaritimeNavigationAid gml:id="b">
>>     <gml:name>Eddystone Lighthouse</gml:name>
>>     <gml:identifier 
>> codeSpace="http://example.org/maritime/navaid/">2650253</gml:identifier>
>>     <geo>
>>         <gml:Point gml:id="b-p1" srsDimension="2" srsName="EPSG:4326">
>>             <gml:pos>50.2 -4.3</gml:pos>
>>         </gml:Point>
>>     </geo>
>>     <lightCharacteristic>
>>         ...
>>     </lightCharacteristic>
>> </MaritimeNavigationAid>
>>
>> So we have two Features (which we collectively have agreed are 
>> "spatial things"), with identifiers 
>> <http://example.com/sar/features/vo/EDY> and 
>> <http://example.org/maritime/navaid/2650253>. Respectively, the XML 
>> elements that describe these features are identified as "a" and "b" 
>> using the @gml:id attribute.
>>
>> If we are using "indirect identification" then _both_ 
>> <http://example.com/sar/features/vo/EDY> and 
>> <http://example.org/maritime/navaid/2650253> are treated as 
>> identifiers for the _real_ Eddystone Lighthouse; we simply don't care 
>> to differentiate between the real world thing and the information 
>> record. In which case, <owl:sameAs>  would seem sufficient? The 
>> "height" and "lightCharacteristic" properties are both applicable to 
>> the real Eddystone Lighthouse. Some judgement would be required to 
>> decide which point geometry ("geo" or "geometry" property) is 
>> considered "best".
>>
>> The way I think about it, @gml:id is more like the identifier for a 
>> named graph; a container for a set of properties ...
>>
>> Am I missing something???
>>
>> Jeremy
>>
>>
>> [1]: http://w3c.github.io/sdw/bp/#spatial-things-features-and-geometry
>>
>> On Wed, 31 Aug 2016 at 12:42 Joshua Lieberman 
>> <jlieberman@tumblingwalls.com <mailto:jlieberman@tumblingwalls.com>> 
>> wrote:
>>
>>     If we are asserting that spatial data on the Web is "always"
>>     feature data that represents a real world entity, then yes, we
>>     don't have the general Web "is it or isn't it physical" ambiguity
>>     and can assume that a feature data identifier also and indirectly
>>     identifies the feature. That still leaves a gap in expressing
>>     whether two feature data entities represent the same real world
>>     entity. Perhaps we need a "sameFeatureAs" predicate to address this.
>>
>>     Josh
>>
>>     Joshua Lieberman, Ph.D.
>>     Principal, Tumbling Walls Consultancy
>>     Tel/Direct: +1 617-431-6431
>>     jlieberman@tumblingwalls.com <mailto:jlieberman@tumblingwalls.com>
>>
>>     On Aug 31, 2016, at 07:29, Frans Knibbe <frans.knibbe@geodan.nl
>>     <mailto:frans.knibbe@geodan.nl>> wrote:
>>
>>>     Hello,
>>>
>>>     As stated before, I don't think the httpRange-14 problem exists
>>>     in our domain of discourse. I think (and hope) that confusion
>>>     can only occur when the things that are described are digital
>>>     things, or things that can be transmitted over a computer
>>>     network, like web pages or mail boxes. It seems to me that
>>>     spatial things are never that type of thing. Therefore there is
>>>     no reason to take precautions against possible confusion.
>>>
>>>     That probably means +1.
>>>
>>>     Greetings,
>>>     Frans
>>>
>>>
>>>     On 31 August 2016 at 09:50, Jeremy Tandy <jeremy.tandy@gmail.com
>>>     <mailto:jeremy.tandy@gmail.com>> wrote:
>>>
>>>         Thanks Rob & Clemens ...
>>>
>>>         On Wed, 31 Aug 2016 at 08:30, Clemens Portele
>>>         <portele@interactive-instruments.de
>>>         <mailto:portele@interactive-instruments.de>> wrote:
>>>
>>>             +1
>>>
>>>
>>>             On 30 August 2016 at 10:10:26, Jeremy Tandy
>>>             (jeremy.tandy@gmail.com <mailto:jeremy.tandy@gmail.com>)
>>>             wrote:
>>>
>>>>             Hi. It would be good to close this issue out & include
>>>>             our collective recommendation in the BP doc working draft.
>>>>
>>>>             PROPOSAL: SDW working group recommends use of "indirect
>>>>             identifiers" for spatial things
>>>>
>>>>             ... I'll start the voting.
>>>>
>>>>             +1
>>>>
>>>>             Jeremy
>>>>
>>>>             (BTW, to make sense of the PROPOSAL you'll need to read
>>>>             the email thread)
>>>>
>>>>             On Fri, 26 Aug 2016 at 10:12 Linda van den Brink
>>>>             <l.vandenbrink@geonovum.nl
>>>>             <mailto:l.vandenbrink@geonovum.nl>> wrote:
>>>>
>>>>                 So… do we agree we can recommend indirect
>>>>                 identifiers, or do we try to fix the issue with
>>>>                 getting the correct identifier as Rob describes?
>>>>
>>>>
>>>>                 While waiting for this I’ve updated the issue and
>>>>                 the text referring to the issue in BP6.
>>>>
>>>>
>>>>                 *Van:* Rob Atkinson [mailto:rob@metalinkage.com.au
>>>>                 <mailto:rob@metalinkage.com.au>]
>>>>                 *Verzonden:* woensdag 24 augustus 2016 13:56
>>>>                 *Aan:* Jeremy Tandy; Phil Archer; Linda van den
>>>>                 Brink; Bill Roberts
>>>>
>>>>
>>>>                 *CC:* SDW WG Public List
>>>>
>>>>                 *Onderwerp:* Re: Clarification required: BP6 "use
>>>>                 HTTP URIs for spatial things"
>>>>
>>>>
>>>>                 Hi
>>>>
>>>>
>>>>                 Agree this is a real concern - people cant be
>>>>                 blamed for doing the obvious, if dumb, thing..
>>>>
>>>>
>>>>                 I think we should take note of best practice in the
>>>>                 HTML world - which is often to include a citable
>>>>                 link to a resource in the rendered view.  Or a
>>>>                 "share" or something similar. We can also put
>>>>                 fairly explicit annotation in machine-readable code
>>>>                 - stating that the resource is about the URI - and
>>>>                 even notes saying when citing this resource use the
>>>>                 URI....
>>>>
>>>>
>>>>                 I'd also like to see browsers evolve to offer you
>>>>                 the original link or the redirected when cutting
>>>>                 and pasting - how hard can it be!
>>>>
>>>>
>>>>                 Maybe we can get Ed to ask around Google Chrome
>>>>                 team for suggestions on how best to handle this :-)
>>>>
>>>>
>>>>                 Rob
>>>>
>>>>
>>>>
>>>>
>>>>                 On Wed, 24 Aug 2016 at 18:27 Jeremy Tandy
>>>>                 <jeremy.tandy@gmail.com
>>>>                 <mailto:jeremy.tandy@gmail.com>> wrote:
>>>>
>>>>                     Yes, I think so ... And we should do so if we
>>>>                     are recommending "indirect identification".
>>>>
>>>>                     Jeremy
>>>>
>>>>                     On Wed, 24 Aug 2016 at 09:24, Phil Archer
>>>>                     <phila@w3.org <mailto:phila@w3.org>> wrote:
>>>>
>>>>                         Bill's comments also made me think about
>>>>                         some of the classic arguments,
>>>>                         such as that a lake doesn't have a last
>>>>                         updated date and isn't 435KB
>>>>                         big. Which are true, however, that kind of
>>>>                         metadata generally comes from
>>>>                         the server, i.e. the HTTP layer. That's an
>>>>                         over simplification but the
>>>>                         point is that it is relatively easy to
>>>>                         avoid deliberately creating
>>>>                         misleading metadata - metadata about the
>>>>                         doc rather than the thing it
>>>>                         describes - and it's also generally easy to
>>>>                         avoid looking for that metadata.
>>>>
>>>>                         Is there scope for some BP advice there?
>>>>
>>>>                         Phil.
>>>>
>>>>                         On 24/08/2016 08:25, Jeremy Tandy wrote:
>>>>                         > Thanks Linda. More clear examples where
>>>>                         being "correct" (in terms of
>>>>                         > avoiding uri collisions by using two
>>>>                         distinct uris) is making things worse
>>>>                         > because users take the wrong one!
>>>>                         >
>>>>                         > So, as a WG, are we content to recommend
>>>>                         this "indirect identification"
>>>>                         > pattern where thing & info resource
>>>>                         identifiers are conflated?
>>>>                         >
>>>>                         > Bill has added some good points about how
>>>>                         to avoid impacts of uri
>>>>                         > collision- by using the (dataset)
>>>>                         metadata to talk about licenses and
>>>>                         > creators for the information ...
>>>>                         > On Wed, 24 Aug 2016 at 07:52, Linda van
>>>>                         den Brink <l.vandenbrink@geonovum.nl
>>>>                         <mailto:l.vandenbrink@geonovum.nl>>
>>>>                         > wrote:
>>>>                         >
>>>>                         >> Experience from the Netherlands: we have
>>>>                         the id/doc pattern in our URI
>>>>                         >> strategy, based on the Cool URIs note
>>>>                         [8] and the ISA study on persistent
>>>>                         >> identifiers [9].
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> That being said, same as Bill I also
>>>>                         notice data users getting confused
>>>>                         >> and generally using the /doc/  URI as
>>>>                         that is the one they can copy from
>>>>                         >> their browser address bar. This is not
>>>>                         only casual confusion but also ends
>>>>                         >> up in published information resources.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> You see this, for example, all over the
>>>>                         CB-NL which is a vocabulary for
>>>>                         >> the building sector and contains links
>>>>                         to other Dutch standards such as
>>>>                         >> IMGeo, an information model and
>>>>                         vocabulary for large scale topography. E.g.
>>>>                         >> the CB-NL concept of ‘Gebouw’ (Building)
>>>>                         [10]  links to two IMGeo concepts
>>>>                         >> ‘Pand’ (building part) and ‘Overig
>>>>                         Bouwwerk’ (other construction) using
>>>>                         >> their /doc/ URIs. If you click on Pand
>>>>                         (which doesn’t have its own landing
>>>>                         >> page in CB-NL so I can’t include the
>>>>                         link) you will see it includes the
>>>>                         >> /doc/  URI as the identifier of Pand.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> This is an example where it occurs in
>>>>                         vocabularies, but I also see it
>>>>                         >> happen with identifiers for data instances.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> [8]: https://www.w3.org/TR/cooluris/
>>>>                         >>
>>>>                         >> [9]:
>>>>                         >>
>>>>                         https://joinup.ec.europa.eu/sites/default/files/D7.1.3%20-%20Study%20on%20persistent%20URIs_0.pdf
>>>>                         >> 10: http://ont.cbnl.org/cb/def/Gebouw
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Linda
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> *Van:* Jeremy Tandy
>>>>                         [mailto:jeremy.tandy@gmail.com
>>>>                         <mailto:jeremy.tandy@gmail.com>]
>>>>                         >> *Verzonden:* dinsdag 23 augustus 2016 20:57
>>>>                         >> *Aan:* Bill Roberts
>>>>                         >> *CC:* SDW WG Public List
>>>>                         >> *Onderwerp:* Re: Clarification required:
>>>>                         BP6 "use HTTP URIs for spatial
>>>>                         >> things"
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Thanks Bill. Sounds very coherent ... I
>>>>                         hoped for some responses such as
>>>>                         >> this based on practical experience. Jeremy
>>>>                         >>
>>>>                         >> On Tue, 23 Aug 2016 at 19:41, Bill
>>>>                         Roberts <bill@swirrl.com
>>>>                         <mailto:bill@swirrl.com>> wrote:
>>>>                         >>
>>>>                         >> ah Jeremy, you are a brave man to poke
>>>>                         the sleeping beast of httpRange-14.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> But I'll get my thoughts in early, then
>>>>                         I can tune out of the ensuing mail
>>>>                         >> avalanche :-)
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> When publishing Linked Data about places
>>>>                         we (at Swirrl) generally do the
>>>>                         >> id/doc fandango, but to be honest I
>>>>                         think data users either don't notice,
>>>>                         >> or they get confused by it.  In the
>>>>                         applications we are working with (and I
>>>>                         >> acknowledge that others may have
>>>>                         different applications and different
>>>>                         >> experiences), it wouldn't cause any
>>>>                         problems to have a single URI, the 'id'
>>>>                         >> URI if you like. We just don't find a
>>>>                         need to say anything about the /doc/
>>>>                         >> URI. If we were starting again, I'd
>>>>                         probably ditch the /doc/ and the 303
>>>>                         >> and rely on context and a little bit of
>>>>                         documentation to make it clear what
>>>>                         >> we mean.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> The place where we find a need to talk
>>>>                         about creators and licences and
>>>>                         >> modified dates is in metadata about
>>>>                         datasets where a dataset might be a
>>>>                         >> collection of information about a bunch
>>>>                         of places - and we treat datasets
>>>>                         >> as an 'information resource'. If someone
>>>>                         requests a dataset URI we return a
>>>>                         >> status code of 200 and the dataset
>>>>                         metadata as the response. That metadata
>>>>                         >> includes info on where to get all the
>>>>                         contents of the dataset if you want
>>>>                         >> that.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> By the way, though it's sensible and
>>>>                         consistent, I find that the implied
>>>>                         >> and parallel property stuff makes it
>>>>                         more rather than less complicated.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Bill
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> On 23 August 2016 at 17:37, Jeremy Tandy
>>>>                         <jeremy.tandy@gmail.com
>>>>                         <mailto:jeremy.tandy@gmail.com>> wrote:
>>>>                         >>
>>>>                         >> All-
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Linda has done a great job of
>>>>                         consolidating the best practices are use of
>>>>                         >> identifiers. We have just one [1] now.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Reading though just now, it occurred to
>>>>                         me that there's still an open
>>>>                         >> issue about identifier assignment ...
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> W3C's Architecture of the World Wide Web
>>>>                         constraint "URIs identify a
>>>>                         >> single resource" [2] asserts "Assign
>>>>                         distinct URIs to distinct resources"
>>>>                         >> in order to avoid URI collisions [2a]
>>>>                         which "often imposes a cost in
>>>>                         >> communication due to the effort required
>>>>                         to resolve ambiguities".
>>>>                         >> Discussions from earlier years in UK Gov
>>>>                         Linked Data working group (and
>>>>                         >> elsewhere) concluded that the "real
>>>>                         world thing" and "information resource
>>>>                         >> that describes the real world thing" are
>>>>                         separate resources. I think this
>>>>                         >> is based on a (purist?) view when
>>>>                         working with RDF of needing to be totally
>>>>                         >> clear on "what's the subject" of each
>>>>                         triple ... the thing or the document.
>>>>                         >> This manifests as URIs with `id` or
>>>>                         `doc` included somewhere to distinguish
>>>>                         >> between the resources and some RDF
>>>>                         triples to clarify that the doc resource
>>>>                         >> is talking about the thing resource etc..
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> (dangerously close to "httpRange-14" [3]
>>>>                         here ... let's avoid that bear
>>>>                         >> trap)
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Jeni Tennison's "URLs in Data Primer"
>>>>                         draft TAG note captures this
>>>>                         >> practice in §5.3 "Publishing data" [4]:
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> ```
>>>>                         >>
>>>>                         >> Publishers can help enable more accurate
>>>>                         merging of data from different
>>>>                         >> sites if they support URLs for each entity
>>>>                         >>
>>>>                         <https://www.w3.org/TR/urls-in-data/#dfn-entity>
>>>>                         they or other sites may
>>>>                         >> wish to describe, separate from the
>>>>                         landing pages
>>>>                         >>
>>>>                         <https://www.w3.org/TR/urls-in-data/#dfn-landing-page>
>>>>                         or records
>>>>                         >>
>>>>                         <https://www.w3.org/TR/urls-in-data/#dfn-record>
>>>>                         that they publish.
>>>>                         >>
>>>>                         >> ```
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Yet Architecture of the World Wide Web
>>>>                         §2.2.3 "Indirect identification"
>>>>                         >> [5] notes that:
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> ```
>>>>                         >>
>>>>                         >> To say that the URI
>>>>                         "mailto:nadia@example.com
>>>>                         <mailto:nadia@example.com>" identifies both an
>>>>                         >> Internet mailbox and Nadia, the person,
>>>>                         introduces a URI collision.
>>>>                         >> However, we can use the URI to
>>>>                         indirectly identify Nadia. Identifiers are
>>>>                         >> commonly used in this way.
>>>>                         >>
>>>>                         >> ```
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> This is consistent with what I recall
>>>>                         TimBL saying at TPAC-2015 in regards
>>>>                         >> to Vcard; come the finish, no one really
>>>>                         cares to distinguish between the
>>>>                         >> thing and its associated information
>>>>                         resource.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> ... And in most cases, one can use
>>>>                         context to determine whether a
>>>>                         >> statement concerns the thing or the
>>>>                         information resource. In those cases
>>>>                         >> where you can't, "URLs in Data Primer"
>>>>                         suggests some mechanisms to mitigate
>>>>                         >> such confusion [6][7].
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> I think that in our SDW WG discussion we
>>>>                         have concluded that we _are_
>>>>                         >> content to use "indirect identification"
>>>>                         - e.g. that we use URIs that
>>>>                         >> conflate the thing and document resource.
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Please can we confirm this? Assuming
>>>>                         that indirect identification is
>>>>                         >> "approved" as best practice, then it
>>>>                         seems prudent to add a note to the BP
>>>>                         >> document saying "don't worry about
>>>>                         distinguishing between thing and
>>>>                         >> resource; indirect identification is
>>>>                         fine" (etc.)
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> Thanks, Jeremy
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >> [1]:
>>>>                         http://w3c.github.io/sdw/bp/#globally-unique-ids
>>>>                         >>
>>>>                         >> [2]:
>>>>                         https://www.w3.org/TR/webarch/#pr-uri-collision
>>>>                         >>
>>>>                         >> [2a]:
>>>>                         https://www.w3.org/TR/webarch/#URI-collision
>>>>                         >>
>>>>                         >> [3]:
>>>>                         https://www.w3.org/2001/tag/group/track/issues/14
>>>>                         >>
>>>>                         >> [4]:
>>>>                         https://www.w3.org/TR/urls-in-data/#publishing-data
>>>>                         >>
>>>>                         >> [5]:
>>>>                         https://www.w3.org/TR/webarch/#indirect-identification
>>>>                         >>
>>>>                         >> [6]:
>>>>                         https://www.w3.org/TR/urls-in-data/#documenting-properties
>>>>                         >>
>>>>                         >> [7]:
>>>>                         https://www.w3.org/TR/urls-in-data/#authoring-specifications
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >>
>>>>                         >
>>>>
>>>>                         --
>>>>
>>>>
>>>>                         Phil Archer
>>>>                         W3C Data Activity Lead
>>>>                         http://www.w3.org/2013/data/
>>>>
>>>>                         http://philarcher.org <http://philarcher.org/>
>>>>                         +44 (0)7887 767755
>>>>                         <tel:%2B44%20%280%297887%20767755>
>>>>                         @philarcher1
>>>>
>>>
>


-- 
Krzysztof Janowicz

Geography Department, University of California, Santa Barbara
4830 Ellison Hall, Santa Barbara, CA 93106-4060

Email: jano@geog.ucsb.edu
Webpage: http://geog.ucsb.edu/~jano/
Semantic Web Journal: http://www.semantic-web-journal.net
Received on Thursday, 1 September 2016 21:43:19 UTC

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