[dxwg] Issue with dct:hasPart as described in DCAT (#1205)

jakubklimek has just created a new issue for https://github.com/w3c/dxwg:

== Issue with dct:hasPart as described in DCAT ==
I think there is possibly a set of issues with `dct:hasPart` as it is currently described in DCAT.

1. In the diagram and [in Catalog description](https://www.w3.org/TR/vocab-dcat-2/#Property:catalog_has_part) it has a domain (`dcat:Catalog`) and a range (`dcat:Resource`) defined.

As I [expressed elsewhere](https://github.com/w3c/dxwg/issues/725#issuecomment-513442046), I have a problem with DCAT imposing domains and ranges on external properties, as this is, in my opinion, basically saying "whoever uses `dct:hasPart` anywhere, from now on, the instances of subjects are (among other things) `dcat:Catalog`s and instances of objects are (among other things) `dcat:Resource`s.", which I think is undesirable.

However, even if I view this statement only "in the context of DCAT", this is still problematic due to a second issue:

2. In the usage note of [dcat:qualifiedRelation](https://www.w3.org/TR/vocab-dcat-2/#Property:resource_qualified_relation) it says:

> Used to link to another resource where the nature of the relationship is known but does not match one of the standard [DCTERMS] properties (dct:hasPart, ...

and in the usage note of the [Relationship class](https://www.w3.org/TR/vocab-dcat-2/#Class:Relationship) it says:

> Use to characterize a relationship between datasets, and potentially other resources, where the nature of the relationship is known but is not adequately characterized by the standard [DCTERMS] properties (dct:hasPart

From both usage notes I gather that if I want to model that one dataset is part of another dataset (or a dataset series), I would use `dct:hasPart`, not a qualified relation. This again has issues:

3. The work on dataset series was moved to DCAT 3 (#868 #806), however, the usage notes above suggest `dct:hasPart` should be used, not qualified relation, for "part of" relationship. This potentially interferes with the usage of qualified relation for dataset series in DCAT 3.
4. If `dct:hasPart` was used, even in scope of DCAT, my `dcat:Dataset` representing the series would also become `dcat:Catalog` thanks to the [domain definition](https://www.w3.org/TR/vocab-dcat-2/#Property:catalog_has_part), which I also see as an undesired side-effect, and potentially interfering with the usage of `dct:hasPart` for dataset series in DCAT 3 unless we say that a dataset representing a dataset series is in fact a catalog.


Please view or discuss this issue at https://github.com/w3c/dxwg/issues/1205 using your GitHub account

Received on Tuesday, 14 January 2020 15:49:06 UTC