Re: Meaning of identifierSpace and schemaSpace

Historically in Freebase the Types themselves were grouped under Domains
sometimes.

We had Domains like /business and /music etc.
and each Type in the Domain (like "artist") had an ID that showed which
domain it was under like this Type "/music/artist".

Then the more general concept was namespaces and keys
https://developers.google.com/freebase/guide/basic_concepts

Wikidata Items directly translate to Freebase Topic MIDs ( like /m/0dgw9r
<https://tools.wmflabs.org/freebase/m/0dgw9r> )

OId MQL ... but this might help you understand... When you inserted a new
value into Freebase you would get back the identifier MID of the triple, in
this case upon inserting the key value "eol" into the "/biology" namespace
(which is essentially a Domain)

[{
  "id":   "/m/0cnstys",
  "type": "/type/namespace",
  "key": [{
    "connect":   "insert",
    "namespace": "/biology",
    "value":     "eol"
  }]
}]

https://groups.google.com/forum/#!searchin/freebase-discuss/jeff$20prucher$20authority|sort:date/freebase-discuss/qiKeBzTMsks/rDtwPUNDClQJ


https://groups.google.com/forum/#!searchin/freebase-discuss/jeff$20prucher$20authority|sort:date/freebase-discuss/WdwYwZKSLtM/6Qc5EosrG28J


https://groups.google.com/forum/#!searchin/freebase-discuss/jeff$20prucher$20authority|sort:date/freebase-discuss/OoRk6BsxWyQ/jCXs-PSn3woJ


https://groups.google.com/forum/#!searchin/freebase-discuss/mql$20namespace|sort:date/freebase-discuss/KMQRKrcTYck/zPKBnyncOj4J


*My initial reaction is that the schemaSpace is more about Domains and that
the identifierSpace is about namespaces and keys* (where we stored unique
identifiers and was the old soft key system).
Since Wikidata has no direct Types or Domains, there is nothing to
translate there I think.

Thad
https://www.linkedin.com/in/thadguidry/


On Tue, Sep 24, 2019 at 5:15 AM Antonin Delpeuch <antonin@delpeuch.eu>
wrote:

> Hi all,
>
> I have a question about the exact meaning of the identifierSpace and
> schemaSpace fields in reconciliation services. This is one thing I would
> like document better in the specifications.
>
> My understanding is that these are URIs which represent the type of
> entities and properties used by the service. Can we have a more precise
> definition than that?
>
> The canonical value for both of these is
> "http://rdf.freebase.com/ns/type.object.id", which was used in the
> Freebase reconciliation service, but can of course no longer be accessed
> (if it ever was? sometimes URIs are not meant to be resolved in a browser).
>
> This canonical value is used by many other reconciliation services, even
> if they do not use Freebase ids at all: for instance, the OCCRP endpoint
> uses it. Is it desirable?
>
> In the Wikidata service I have used "http://www.wikidata.org/entity/" as
> identifierSpace and "http://www.wikidata.org/prop/direct/" as
> schemaSpace. The idea behind this choice was that you can get a RDF URI
> for identifiers and properties by concatenating their ids to these
> prefixes. But that was totally a guess on my part. Perhaps I should have
> used actual URIs there? Which ones?
>
> So, in short, I would like a precise definition of the identifierSpace
> and schemaSpace fields, which would unambiguously inform implementers
> about what value they should have in their own services.
>
> Thanks,
>
> Antonin
>
>
>
>