On 6 January 2018 at 02:51, Dan Brickley <danbri@danbri.org> wrote:



May I suggest we explore some modest tweaks to the definition, e.g. 

Instead of "catalog for the item, or, as a qualifier of P528 – catalog for which the 'catalog code' is valid "

...say: "a catalog (not necessarily public) which includes the item, or, as a qualifier of P528 – catalog for which the 'catalog code' is valid "

Changes:

1. (not essential) the "a" just emphasizes that something might show up in several catalogs.
2. "not necessarily public" clarifies a more inclusive notion of catalog that would cover grassroots and developing/new projects etc as well as big famous brick-and-mortar collections.
3. "includes" rather than "for", again in spirit of (1.).


Hi Dan,  I see you have made same misinterpretation as me after looking at P972. Andy's response to my message caused me to reinterpret 

"catalog for the item"

as "catalog produced or published by or for the item (where item = exhibition or similar)", evidenced by the example on the talk page
https://www.wikidata.org/wiki/Q15087813  which has a catalog property to store the catalog it "owns".

Your suggestion to replace "for" with "includes" seemed reasonable to me, but that is not what the "for" means apparently. The language is not clear, and my longer attempt above isn't great either. The main point is that "for" means something like "owned by" and not "which it is a member of"

From the intent of the description and examples in https://www.wikidata.org/wiki/Property_talk:P972  it looks like P972 as a qualifier imparts the sense of item is "member of <catalog>", but as a property means item is "owner of <catalog>"
I'm not sure that dual usage makes sense, and certainly it has caused confusion in how the property is used, since the bulk of the usages of P972 as a property appear to intend "member of <catalog>", but are indistinguishable from those that intend "owner of <catalog>", which is apparently the correct use.

I said I'd take this up further on the property talk page, which I will. Just wanted to make a non-obvious correction in case the confusion spread. I'm also happy to see another concrete example of this misinterpretation, so it's not just me!

 Charles.