Hoi,
Sorry for being dense.. What is wrong with there being no value ? Having
a "no value" is imho understanding only a complication of saying nothing...
Why not say nothing in the first place ?
Thanks,
GerardM
On 22 April 2015 at 21:52, Markus Krötzsch <
markus(a)semantic-mediawiki.org> wrote:
Hi Thomas,
On 22.04.2015 20:06, Thomas Douillard wrote:
> Hi, there is items about Wikibase data model in Wikidata (created by
> me,
> but not only)
>
> If I understand correctly, they could be cited in the semantic web as
>
https://www.wikidata.org/entity/Q19798647
>
"No value" is exactly that: not a value. It should not be confused with
a (definite) value that is used with claims (as the item description seems
to suggest). The reason why we introduced "no value" was to be able to say
this without resorting to a "special value" to represent this.
You can also find some rationale about this in our article "Wikidata: a
free collaborative knowledgebase" (see
https://ddll.inf.tu-dresden.de/web/Article4002/en). Basically, the
main point is that, if you are querying for two people with a common child,
you wouldn't want to get pairs of people who both have "novalue" as a
value
for "child". The same is true for "some value" (sometimes referred to
as
"unknown value") -- again, if this would be a definite "special"
value, and
be treated like a value in queries, it would lead to wrong results.
Cheers,
Markus
> (If they are kept /o\)
>
> Tom²
>
>
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