- From: Dan Brickley <danbri@danbri.org>
- Date: Tue, 4 Dec 2018 13:25:30 -0800
- To: Dave Reynolds <dave.e.reynolds@gmail.com>
- Cc: Semantic Web <semantic-web@w3.org>, danbri@google.com
- Message-ID: <CAFfrAFqLg6f4gbfr691awZs57=AG41htCwWPmn8gmcOiu_v-tA@mail.gmail.com>
("Details like URIs or bNodes seem to me rather down in the noise.")
Thanks, Dave. This chimes with a lot of our experience at Google using
Schema.org data (roughly RDF triples) from the Web, fwiw.
Dan
On Tue, 4 Dec 2018, 03:30 Dave Reynolds <dave.e.reynolds@gmail.com wrote:
> I don't want to get embroiled in the main thread(s) but, just in case
> anyone is *really* dealing with UK addresses rather than using them as
> rhetorical examples, then ...
>
> On 03/12/2018 23:37, Anthony Moretti wrote:
> > I see your point Hugh, especially in your case because for UK addresses
> > consisting of only house number and postcode structural equality is
> > sufficient for address equality. Decentralized will work very well in
> > that case.
>
> Sadly that's a long way from being true. UK addresses within a postcode
> my be identified by house name, house name + number, business name (with
> no house name or number at all), any of those plus a secondary address
> etc etc. Even when there's a house "number" sometimes its actually a
> number range not a single number and there's considerable ambiguity on
> how those ranges are expressed and what the "definitive" range for a
> given property really is.
>
> Identity of UK addresses is simply not something you can express in OWL
> or any logic close to it. You need an address reconciliation algorithm
> to map your address to an maintained identifier set such as a UPRN or
> UDPRN. The reconciliation process will have error rates that you will
> need to manage and recover from, there's no closed, guaranteed algorithm.
>
> Once you have the UPRN or UDPRN or whatever you can create URI's or some
> inverse functional property as you wish. Except that even then the
> official identifier schemes like that aren't perfect and have ...
> oddities ... in them that can still mess you up.
>
> Generating unique keys for resources based on hashing a few properties
> is all very well in simple cases but, at least in my experience, real
> world problems are nothing like that simple clean. You need serious
> effort to create and maintain identifier schemes and to reconcile source
> data against those schemes. Details like URIs or bNodes seem to me
> rather down in the noise.
>
> Dave
>
> > On Mon, Dec 3, 2018 at 3:07 PM Nathan Rixham <nathan@webr3.org
> > <mailto:nathan@webr3.org>> wrote:
> >
> > Hugh, do you mean something like bnode.id <http://bnode.id> =
> > sha256(serialise(bnode))
> >
> > On Mon, 3 Dec 2018, 22:58 Hugh Glaser <hugh@glasers.org
> > <mailto:hugh@glasers.org> wrote:
> >
> > This is not directly about blank nodes, but is a reply to a
> > message in the thread.
> >
> > I’m certainly agreeing that we should work towards common
> > understanding of Thing equality.
> > And addresses are a great place to start.
> > In order for equality to be defined, I think that means you
> > first need an idea of what an unambiguous address looks like.
> >
> > Having an oracle that defines what an unambiguous Thing looks
> > like is one organisational structure, and it would be great if
> > schema.org <http://schema.org> could lead the way.
> > It particularly helps people who just want an off the shelf
> > solution, especially if they have no knowledge of the Thing
> domain.
> >
> > However I (and perhaps David Booth) am after something more
> > anarchic, that can function in a decentralised way (if I dare to
> > use that term! :-) )
> > For example, I might decide that I think that House Number and
> > PostCode is enough.
> > (UK people will know that this is a commonly-used way of
> > choosing an address, although it may well not be satisfactory
> > for some purposes, I’m sure.)
> > That may well be sufficient for me to interwork with datasets
> > from Companies House, the Land Registry and a bunch of other
> > UK-based organisations, plus many other datasets.
> >
> > Having a simple standard way to create keys for such things
> > facilitates that, without any standardisation process and all
> > that entails in weaknesses and strengths of trying to get
> > agreement on what an unambiguous address might look like on a
> > world scale for all purposes.
> >
> > Just generating a URI, without needing to make any service calls
> > (having found where they are and chosen the one you want and
> > compromised on it, etc.) or anything seems to me a way of making
> > all the interlinking so much more accessible for us all.
> > It is even future proof:- using such a URI means that if it is
> > about something new (UK postcodes change all the time :-(, and
> > there are more dead ones than live ones), the oracle doesn’t
> > tell me anything it didn’t have until I ask again.
> > In a key-generating world, my new shiny key will slowly align
> > with all the other key URIs as they get created.
> >
> > So yeah, all strength to anyone who wants to take on the central
> > roles, but not at the expense of killing the anarchic solution,
> > please.
> >
> > Cheers
> >
> > > On 3 Dec 2018, at 22:10, Anthony Moretti
> > <anthony.moretti@gmail.com <mailto:anthony.moretti@gmail.com>>
> > wrote:
> > >
> > > Cheers for agreeing William. On the topic of incomplete blank
> > nodes Henry I'd give them another type, the partial address
> > example you give I'd give the type AddressComponent, or
> > something to that effect. I could be wrong, but it's not a valid
> > Address if it's a blank node and no other information in the
> > graph completes it.
> > >
> > > Anthony
> > >
> > > On Mon, Dec 3, 2018 at 1:56 PM William Waites
> > <wwaites@tardis.ed.ac.uk <mailto:wwaites@tardis.ed.ac.uk>>
> wrote:
> > > > standards like schema:PostalAddress should possibly define
> > relevant
> > > > operations like equality checking too.
> > >
> > > Exactly.
> > >
> > >
> >
>
>
Received on Tuesday, 4 December 2018 21:26:07 UTC