Hi Osma,

sorry for jumping in late. I've been at ELAG last week, talking about a very similar topic (Wikidata as authority linking hub, https://hackmd.io/p/S1YmXWC0e). Our use case was porting an existing mapping between RePEc author IDs and GND IDs into Wikidata (and furtheron extending it there). In that course, we had to match as many persons as possible on the GND as well as on the RePEc side (via Mix'n'match), before creating new items. The code used for preparing the (quickstatements2) insert statements is linked from the slides.

Additionally, I've added ~12,000 GND IDs to Wikidata via their existing VIAF identifiers (derived from a federated query on a custom VIAF endpoint and the public WD endpoint - https://github.com/zbw/sparql-queries/blob/master/viaf/missing_gnd_id_for_viaf.rq). This sounds very similar to your use case; also another query which can derive future STW ID properties from the existing STW-GND mapping (https://github.com/zbw/sparql-queries/blob/master/stw/wikidata_mapping_candidates_via_gnd.rq - currently hits a timeout at the WD subquery, but worked before). I would be happy if that could be helpful.

The plan to divide the m'n'm catalogs (places vs. subjects) makes sense for me, we plan the same for STW. I'm not sure, if a restriction to locations (Q17334923, or something more specific) will match also all subclasses, but Magnus could perhaps take care of that when you send him the files.

Cheers, Joachim

> -----Ursprüngliche Nachricht-----
> Von: Wikidata [mailto:wikidata-bounces@lists.wikimedia.org] Im Auftrag von
> Osma Suominen
> Gesendet: Dienstag, 6. Juni 2017 12:19
> An: Discussion list for the Wikidata project.
> Betreff: [Wikidata] Mix'n'Match with existing (indirect) mappings
>
> Hi Wikidatans,
>
> After several delays we are finally starting to think seriously about mapping the
> General Finnish Ontology YSO [1] to Wikidata. A "YSO ID"
> property (https://www.wikidata.org/wiki/Property:P2347) was added to
> Wikidata some time ago, but it has been used only a few times so far.
>
> Recently some 6000 places have been added to "YSO Places" [2], a new
> extension of YSO, which was generated from place names in YSA and Allärs,
> our earlier subject indexing vocabularies. It would probably make sense to map
> these places to Wikidata, in addition to the general concepts in YSO. We have
> already manually added a few links from YSA/YSO places to Wikidata for newly
> added places, but this approach does not scale if we want to link the thousands
> of existing places.
>
> We also have some indirect sources of YSO/Wikidata mappings:
>
> 1. YSO is mapped to LCSH, and Wikidata also to LCSH (using P244, LC/NACO
> Authority File ID). I digged a bit into both sets of mappings and found that
> approximately 1200 YSO-Wikidata links could be generated from the
> intersection of these mappings.
>
> 2. The Finnish broadcasting company Yle has also created some mappings
> between KOKO (which includes YSO) and Wikidata. Last time I looked at those,
> we could generate at least 5000 YSO-Wikidata links from them.
> Probably more nowadays.
>
>
> Of course, indirect mappings are a bit dangerous. It's possible that there are
> some differences in meaning, especially with LCSH which has a very different
> structure (and cultural context) than YSO. Nevertheless I think these could be a
> good starting point, especially if a tool such as Mix'n'Match could be used to
> verify them.
>
> Now my question is, given that we already have or could easily generate
> thousands of Wikidata-YSO mappings, but the rest would still have to be semi-
> automatically linked using Mix'n'Match, what would be a good way to
> approach this? Does Mix'n'Match look at existing statements (in this case YSO
> ID / P2347) in Wikidata when you load a new catalog, or ignore them?
>
> I can think of at least these approaches:
>
> 1. First import the indirect mappings we already have to Wikidata as
> P2347 statements, then create a Mix'n'Match catalog with the remaining YSO
> concepts. The indirect mappings would have to be verified separately.
>
> 2. First import the indirect mappings we already have to Wikidata as
> P2347 statements, then create a Mix'n'Match catalog with ALL the YSO
> concepts, including the ones for which we already have imported a mapping.
> Use Mix'n'Match to verify the indirect mappings.
>
> 3. Forget about the existing mappings and just create a Mix'n'Match catalog
> with all the YSO concepts.
>
> Any advice?
>
> Thanks,
>
> -Osma
>
> [1] http://finto.fi/yso/
>
> [2] http://finto.fi/yso-paikat/
>
> --
> Osma Suominen
> D.Sc. (Tech), Information Systems Specialist National Library of Finland P.O. Box
> 26 (Kaikukatu 4)
> 00014 HELSINGIN YLIOPISTO
> Tel. +358 50 3199529
> osma.suominen@helsinki.fi
> http://www.nationallibrary.fi
>
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