Re: ACTION-96 linking to related identifiers

Hi Bill, Jon ...

Great content along with some very useful examples that we (BP editors) can
incorporate.

I think that the subject boils down to two best practices ...

>From Expressing spatial data
<http://w3c.github.io/sdw/bp/#bp-expressing-spatial> we have Best Practice
13: Assert known relationships <http://w3c.github.io/sdw/bp/#semantic-rels>
which *will** say something along the lines of "if you know some
relationships between (spatial) Things then publish them - because it's
hard to figure out relationships from scratch" as your examples illustrate.

And From Linking Data <http://w3c.github.io/sdw/bp/#bp-linking> we have Best
Practice 20: Provide meaningful links
<http://w3c.github.io/sdw/bp/#meaningful-links> (include the right
semantics), Best Practice 21: Link to spatial Things
<http://w3c.github.io/sdw/bp/#link-to-spatialthings> (link up the Things
rather than the information objects that describe them e.g. geometry
objects) and Best Practice 22: Link to resources with well-known or
authoritative identifiers
<http://w3c.github.io/sdw/bp/#link-to-auth-identifiers> (reference other
people's well established resources & identifiers thereof). The middle one
of these needs some work methinks because it's clearly useful to link a
Thing to its geometric description ... but we want to create a network of
related resources using the identifiers for the Things.

* "will" say ... because I've not finished writing things up yet :-)

Thanks Bill. Jeremy

On Sun, 29 Nov 2015 at 16:11 Jon Blower <j.d.blower@reading.ac.uk> wrote:

> Hi Bill, all,
>
> Just wanted to say that I found this to be an extremely helpful and
> informative post, thanks!
>
> the BP document might be able to help by categorising some of the most
> common relationships and perhaps suggest examples of appropriate matching
> vocabulary terms.
>
>
> Yes, I agree. Some of these issues are very characteristic of spatial data
> and bang in scope for a BP document I think. We often see abuse of
> owl:sameAs when a weaker term would be more appropriate. Enumerating the
> options and use cases would be very helpful.
>
> (This has particular local relevance to us here - the University of
> Reading is actually mostly in the Wokingham district, although most people
> would still refer to it as part of the Reading urban area. “Colloquial
> Reading” is different from “administrative Reading”, as it is in probably
> most cities.)
>
> Cheers,
> Jon
>
>
> On 26 Nov 2015, at 18:29, Bill Roberts <bill@swirrl.com> wrote:
>
> Hi BP-editors
>
> Here are some initial thoughts on the issues of linking from your own
> Spatial Thing to other identifiers for the same thing or related things.
>
> This action is to expand the text in section 7.2 of the BP draft that
> currently says:
>
> "it's useful to have hyperlinks to things like Geonames, wikipedia, OSM
> etc (see list on the mailing list, keyword: stamp collecting)"
>
> As per http://www.w3.org/DesignIssues/LinkedData.html item 4, it's useful
> for people to link their data to other related data. In this context we're
> most frequently talking about either Spatial Things and/or their geometry.
>
> There are many useful sets of identifiers for spatial things and which
> ones are most useful will depend on context.
>
> I think there are two main challenges here - discovering relevant URIs
> that you might want to connect to, deciding what is the nature of the
> relationship between your original URI and potential link targets, and then
> finding an existing vocabulary term that accurately reflects that
> relationship.
>
> As an example, let's take Edinburgh. In some recent work with the Scottish
> Government, we have an identifier for the City of Edinburgh Council Area -
> i.e. the geographical area that Edinburgh City Council is responsible for:
>
> http://statistics.gov.scot/id/statistical-geography/S12000036
>
> (note that this URI doesn't resolve yet but it will in the next couple of
> months once the system goes properly live)
>
> Here are some identifiers for Edinburgh and/or information about it that
> we might want to link to, together with notes about how I found out about
> them.
>
> http://statistics.data.gov.uk/id/statistical-geography/S12000036
>
> My identifier is directly based on this one, but the Scottish Government
> wanted the ability to create something dereferenceable, potentially with
> additional or different info to the data.gov.uk one.  We're happy these
> two are owl:sameAs
>
> https://en.wikipedia.org/wiki/Edinburgh
> Found by a google search for Edinburgh site:wikipedia.org).  This is a
> page about a closely related but perhaps less specific concept of the
> place. Possible document vs thing distinctions to be made here.  Possible
> relationships: rdfs:seeAlso, schema:sameAs ? foaf:page?
>
> http://dbpedia.org/resource/Edinburgh
> I know the pattern for changing a wikipedia URI into a dbpedia one, so
> found it that way.  Relationship: "more or less the same as" but not sure
> I'd want to go as far as the strict semantics of owl:sameAs
>
> http://data.ordnancesurvey.co.uk/id/50kGazetteer/81482 (Edinburgh)
> Found by OS gazetteer search service for 'Edinburgh' then checking the
> labels of the results that came up.  OS give it a type of 'NamedPlace' and
> give it some coordinates.
>
> http://data.ordnancesurvey.co.uk/id/50kGazetteer/81483 (Edinburgh
> airport)
> Also found by the same OS gazetteer search service for 'Edinburgh'.  This
> is clearly not the same as my original spatial thing, but I might want to
> say something like 'within' or 'hasAirport'.
>
> http://data.ordnancesurvey.co.uk/id/7000000000030505
> Found by a search for 'Edinburgh' in the OS 'Boundary Line' service that
> contains administrative and statistical geography areas in the UK.  The
> first results of the search were parliamentary constituencies - had to
> scroll down and look for one that had a stated rdf:type that matched what I
> was looking for.  It's probably safe to say my identifier is owl:sameAs
> this one.
>
> http://sws.geonames.org/2650225/
> Found with the Geonames search service:
> http://api.geonames.org/search?name=Edinburgh&type=rdf&username=demo
> Once you have found a place in geonames, there are other useful services
> to find things that are nearby etc. Not sure exactly what this is, though
> it has a RDF type of http://www.geonames.org/ontology#Feature
>
> http://www.openstreetmap.org/relation/1920901  (administrative boundary)
> machine readable data:
> http://www.openstreetmap.org/api/0.6/relation/1920901
> Found via the search box at www.openstreetmap.org.
> see also http://nominatim.openstreetmap.org/details.php?place_id=127903534
> and http://www.openstreetmap.org/node/17898859 (node - somewhere around
> the centre of Edinburgh)
> I'm not sure of all the options with OSM - I'm sure others in the WG know
> more -but it has identifiers for nodes, ways and relations, though it seems
> that these identifiers tend to change quite frequently as the map is edited.
>
> The outcome of this example is that it takes a bit of prior knowledge and
> intelligent manual guesswork to find related URIs.  Some services, eg OS,
> have useful search facilities, but the results may still need some
> interpretation. Recommending some standard approach to providing a search
> facility (or 'reconciliation API') for a collection of spatial data might
> be a useful best practice.
>
> Working out how to accurately describe the relationship is hard in general
> and the BP document might be able to help by categorising some of the most
> common relationships and perhaps suggest examples of appropriate matching
> vocabulary terms.
>
>
>
>
>