Re: Addresses have no easy identity was Re: Blank Nodes Re: Toward easier RDF: a proposal

Valuable information Dave, so the trivial case doesn't even exist. Perhaps
the only value then in a structural equality comparison is that in the
absence of a better algorithm or identifier scheme it might reduce the
number of address pairs that a human would need to check.

Anthony

On Tue, Dec 4, 2018 at 3:30 AM 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.
> >          >
> >          >
> >
>
>