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 <mar...@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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