[Lds] ideas/recommendations for JSON-LD serializations

Adrian Pohl pohl at hbz-nrw.de
Mo Apr 23 13:19:26 CEST 2018

Hello Thomas,

I am responding as we also provide ZDB and GND data as well as data from 
the German ISIL registry via lobid and already offer most of the things 
you are asking for. So, you may want to give it a try.

Generally, lobid-gnd is available via https://lobid.org/gnd and is still 
in beta, amongst others because we haven't implemented yet adding labels 
for embedded nodes (see [1] and its prerequisite [2]).

ZDB data is available as part of lobid-resources at 
https://lobid.org/resources. You have to filter by collection to get all 
ZDB resources. [3] Note that the RDF representation of ZDB resources, 
though very similar, differs from that by the ZDB itself, see an 
annotated example at [4].

And if you are also interested in ISIL data (Adressverzeichniss der 
ZDB), then go to lobid-organisations: https://lobid.org/organisations.

On 19.04.2018 14:14, Thomas Gängler wrote:
> Hello,
> currently, we process some JSON-LD dumps (e.g. ZDB and GND) from data 
> available via DNB. Our observations while processing them are following:
> 1. It would be nice, if you could provide line-delimited JSON [1] 
> records (instead of one large JSON object/array (as it is the case right 
> now))

We already provide JSON Lines [5] for lobid-organisations and 
lobid-resources, see [6]. We will also add it for lobid-gnd.

> 2. It would be nice, if the JSON-LD records could be provided in compact 
> JSON-LD [2] (instead of the extended format (as it is the case right 
> now)) + referenced @context* (instead of inline @context)

All lobid services provide compacted JSON-LD with a referenced @context.

> 3. It would be nice, if the (compact) JSON-LD records contain all 
> sub-entities (i.e. there are no separate bnodes, but (if necessary) 
> hierarchical entities), cf. [4], [5] or similar (instead of separate 
> bnode objects in the same hierarchy level (as it is the case right now))

lobid provides JSON-LD documents with one root node and with all other 
nodes embedded in the hierarchy. (This was a main reason and major 
improvement in our move from lobid 1.x to the new version.) We don't add 
the whole data on an embedded node but only provide a label for display 
purposes. (As said above, we are still working on implementing this in 
lobid-gnd.) Further data must be fetched from the linked resource.

> We believe that all recommended changes will lead to a better usability 
> of the provided JSON-LD data. Hence, we and probably other data 
> consumers of the DNB datasets will be happy, if you could implement our 
> proposed ideas.

I agree.

All the best

[1] https://github.com/hbz/lobid-gnd/issues/24
[2] https://github.com/hbz/lobid-gnd/issues/85
[4] http://lobid.org/resources/api#periodikum
[5] http://jsonlines.org/
[6] http://lobid.org/resources/api#content_types

> Best regards,
> Thomas
> *) referenced context requires that you probably need to provide/host 
> the context documents at DNB (instead of, e.g., ZDB Github account [3])
> [1] https://en.wikipedia.org/wiki/JSON_streaming#Line_delimited_JSON
> [2] https://www.w3.org/TR/json-ld-api/#compaction
> [3] https://github.com/Zeitschriftendatenbank/jsonld-context
> [4] https://www.w3.org/Submission/CBD/
> [5] Minimum Spanning Graph: 
> http://onlinelibrary.wiley.com/doi/10.1002/cpe.1623/pdf
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Adrian Pohl
hbz - Hochschulbibliothekszentrum des Landes NRW
Jülicher Straße 6
50674 Köln
Telefon +49-221-40075-235

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