Talk:Q575727

Museum ship identification

Please avoid using instance of (P31) with museum ship (Q575727) (P31 should restricted to identify the ship type [one of Query: claim[31:2235308]]) and rather identify museum ships with has use (P366) = museum ship (Q575727), qualified with start time (P580). -- LaddΩ chat ;) 21:31, 15 April 2015 (UTC)

I've done that everywhere. Run this query to see if any reappear

SELECT DISTINCT ?item ?itemLabel WHERE {
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE]". }
  {
    SELECT DISTINCT ?item WHERE {
      ?item p:P31 ?statement0.
      ?statement0 (ps:P31/(wdt:P279*)) wd:Q575727.
      MINUS {
        ?item p:P31 ?statement1.
        ?statement1 (ps:P31/(wdt:P279*)) wd:Q3456301.
      }
    }
    LIMIT 100
  }
}

Try it!

Vicarage (talk) 08:27, 24 August 2022 (UTC)

It is okay to mark museum ships with has use (P366) = museum ship (Q575727), but I disagree that instance of (P31) should not have an additional (!) museum ship (Q575727) also. I think that gives additional information at a prominent position. -- Gerd Fahrenhorst (talk) 17:13, 24 August 2022 (UTC)

The danger of having multiple tags with the same purpose is that someone will write a filter against one of them and miss all the entries that only have the other. For wikidata to be useful it needs to be consistent and avoid duplication. Vicarage (talk) 19:25, 24 August 2022 (UTC)

I don't think the instance of (P31) statement gives additional information, it gives information that is redundant to the has use (P366) statement. Although duplication of information is sometimes useful on Wikidata (contra Vicarage), in this case it offers no advantage. instance of (P31)=museum ship (Q575727) should be replaced with has use (P366)=museum ship (Q575727) and a constraint set up to enforce. Swpb (talk) 18:41, 30 August 2022 (UTC)

I've changed my mind. I think we should have instance of (P31) = museum ship (Q575727). The reason being that it makes the ship fit in with the hierarchy of museums and tourist attractions and the constraint logic around whether properties like historic county (P7959). This all works much better with instance of (P31) than has use (P366). And its meshes better with the other common fate of ships, which can be an instance of a shipwreck (Q852190) but not have that as a role. No objection to having both properties though. Vicarage (talk) 08:48, 9 November 2022 (UTC)