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Re: Question about identifiers

From: Frans Knibbe <frans.knibbe@geodan.nl>
Date: Fri, 19 Aug 2016 14:03:47 +0200
Message-ID: <CAFVDz42o0eHSD1Am0cEgtNpPfwbznE0W3HN_UuRKn6hPtbj5Vw@mail.gmail.com>
To: "SDW WG (public-sdw-wg@w3.org)" <public-sdw-wg@w3.org>
On 19 August 2016 at 12:10, Ed Parsons <eparsons@google.com> wrote:

> So perhaps best practice is to update the resource at the old URI to point
> to the new one ?
>

That is a possibility, but it would be messy. For individual resources
redirection would have to be set up. That means high maintenance costs and
a high risk of mistakes. And still there would be the risk of
misinterpretation. A human consumer could interpret the first URI
encountered without following it to an alternative URI, still leading to
false data.

But what would be the point anyway? If a  path in the URI like
/{municipality}/{quarter}/{neighbourhood} is for human consumption only it
is not that valuable, I think, assuming that most people don't read URIs.

The only reason I can think of to want to have a hierchical path in a URI
is if web crawlers are known to parse the URI strings themselves (next to
the URI payload). That could in theory lead to improved discoverabilty of
resources. I wonder if that actually happens... Perhaps Ed knows how the
Google crawlers behave in that respect? Or would that be sharing trade
secrets?

Regards,
Frans



> Ed
>
>
> On Fri, 19 Aug 2016 at 11:03 Frans Knibbe <frans.knibbe@geodan.nl> wrote:
>
>> On 19 August 2016 at 11:11, Linda van den Brink <
>> l.vandenbrink@geonovum.nl> wrote:
>>
>>> Yes…  it is generally easier to make meaningless IDs persistent. But it
>>> is nice to have URIs that are human readable. In the Dutch URI strategy we
>>> do advise having human-readable parts in the URI scheme, but say that
>>> officially these mean nothing i.e. we say it is extremely ill-advised to
>>> ascribe any meaning to {concept} **for the machine**. URIs are opaque
>>> in a technical sense. Meanwhile, however, they do give hints to human
>>> readers.
>>>
>>
>> Then how can you tell humans that they can interpret the URI and tell
>> machines that they should not? Is there a mechanism for doing that?
>>
>> Greetings,
>> Frans
>>
>>
>>>
>>>
>>> *Van:* Ed Parsons [mailto:eparsons@google.com]
>>> *Verzonden:* vrijdag 19 augustus 2016 11:02
>>> *Aan:* Frans Knibbe; SDW WG (public-sdw-wg@w3.org)
>>> *CC:* Linda van den Brink; Joshua Lieberman (
>>> jlieberman@tumblingwalls.com); Byron Cochrane
>>> *Onderwerp:* Re: Question about identifiers
>>>
>>>
>>>
>>> While I accept that the current view of URI schemes having no explicit
>>> meaning, I do see great value in the /{municipality}/{quarter}/
>>> {neighbourhood} as a simple way of expressing geographical hierarchy independent of
>>> geometry... What's the worst that could happen ?
>>>
>>>
>>>
>>> Ed
>>>
>>>
>>>
>>>
>>>
>>> On Fri, 19 Aug 2016 at 09:30 Frans Knibbe <frans.knibbe@geodan.nl>
>>> wrote:
>>>
>>> Hi,
>>>
>>>
>>>
>>> A prime requirement of good URI minting is to not put any meaning in the
>>> URI, at least no meaning that is somehow intended for consumers. Everything
>>> that needs to be said about a resource, like its membership of data
>>> collections or its versioning, can be said in the data that is returned
>>> when the URI is dereferenced.
>>>
>>>
>>>
>>> URI schemes like /{municipality}/{quarter}/{neighbourhood} could be
>>> dangerous, because consumers could inadvertently try to derive meaning from
>>> such an URI. The usefulness of such a scheme in URI minting is also
>>> doubtful, because administrative structure can change in time. That could
>>> complicate the URI minting procedures over time.
>>>
>>>
>>>
>>> I do wonder to what extent common web crawlers try to parse URIs and
>>> attach meaning to URI parts.
>>>
>>>
>>>
>>> Regards,
>>>
>>> Frans
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On 18 August 2016 at 22:55, Byron Cochrane <bcochrane@linz.govt.nz>
>>> wrote:
>>>
>>> Hi,
>>>
>>> I like the guidance under the URI-Strategy under Hierarchical URIs
>>> generally, but have some reservations to this intelligent identifiers
>>> approach.
>>> For metadata access I think it is a good thing.  Most metadata for an
>>> individual features will usually reside at the dataset or collection
>>> (better term) level.  This hierarchical approach makes this metadata easy
>>> to access.
>>>
>>> But this built in intelligence makes the permanence of the URIs more
>>> difficult.  For example, administrative boundaries change through mergers
>>> and annexations.  A spatial thing that was in one collection is now in
>>> another.  The URIs for these things then confuse more than help.  URI
>>> redirects are one way to deal with this, but perhaps tracking these
>>> relationships through applied ontologies such as skos:broader and
>>> skos:narrower is the better practice?
>>>
>>> No answers from me here, just questions.
>>>
>>> Cheers,
>>> Byron
>>>
>>> ________________________________________
>>> From: Linda van den Brink [l.vandenbrink@geonovum.nl]
>>> Sent: Thursday, August 18, 2016 8:28 PM
>>> To: Joshua Lieberman (jlieberman@tumblingwalls.com)
>>> Cc: SDW WG (public-sdw-wg@w3.org)
>>> Subject: Question about identifiers
>>>
>>> Hi Josh,
>>>
>>> Coming back to the telecon yesterday:
>>>
>>>
>>> <joshlieberman> Should identifiers be part of a system for the features
>>> of interest?
>>>
>>> joshlieberman: making identifiers part of a system, where the features
>>> are part of the system?
>>> ... for example corresponding to paths in a taxonomy
>>>
>>> Linda: no answer right now, will have to think about it
>>>
>>> Were you talking about recommending some system for creating HTTP URI
>>> identifiers, i.e. some sort of URI strategy or pattern? Specifically where
>>> the features can be organised into some system like a hierarchy, as with
>>> administrative regions? There are some examples from Geonovums testbed here
>>> https://github.com/geo4web-testbed/topic3/wiki/URI-Strategy under
>>> Hierarchical URIs.
>>>
>>> Just trying to understand what you mean… we could add some guidance to
>>> the BP about this. I think that would be helpful.
>>>
>>> Linda
>>>
>>> ______________________________________
>>> Geonovum
>>> Linda van den Brink
>>> Adviseur Geo-standaarden
>>>
>>> a: Barchman Wuytierslaan 10, 3818 LH Amersfoort
>>> p: Postbus 508, 3800 AM Amersfoort
>>> t:  + 31 (0)33 46041 00
>>> m: + 31 (0)6 1355 57 92
>>> e:  l.vandenbrink@geonovum.nl<mailto:r.beltman@geonovum.nl>
>>> i:  www.geonovum.nl<http://www.geonovum.nl/>
>>> tw: @brinkwoman
>>>
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>>>
>>> --
>>>
>>> *Ed Parsons *FRGS
>>> Geospatial Technologist, Google
>>>
>>> Google Voice +44 (0)20 7881 4501
>>> www.edparsons.com @edparsons
>>>
>> --
>
> *Ed Parsons *FRGS
> Geospatial Technologist, Google
>
> Google Voice +44 (0)20 7881 4501
> www.edparsons.com @edparsons
>
Received on Friday, 19 August 2016 12:04:19 UTC

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