Well, I don't know if they would hurt anyone, but I don't think people would go through the extra effort to set them. Here are our current properties. http://www.wikidata.org/wiki/Wikidata:List_of_properties We could categorize them according to mutability, but we'd also need to know how many times each property is used. For historic population values, qualifiers will serve the purpose you want. For presidential terms, I think we will either see "started presidency" and "ended presidency" properties that are added to items for people who have been president, or we will see "administration began" and "administration ended" properties added to items for each presidential term/administration.


Date: Fri, 5 Apr 2013 00:49:04 +0200
From: benedix@zedat.fu-berlin.de
To: wikidata-l@lists.wikimedia.org
Subject: Re: [Wikidata-l] Page history and properties

Good Point! The first things I thougt about were populations and other country, region or city oriented data.

But would two fields that can be set to NULL as default - valid_from -> the beginning of the time, valid_to -> the end of the universe - hurt anyone?



Am Fr 05.04.2013 00:37, schrieb Michael Hale:
I don't have any data to agree or disagree with you about that, but most of the edits I have made have been for films. Most of those claims are immutable.


Date: Fri, 5 Apr 2013 00:34:21 +0200
From: benedix@zedat.fu-berlin.de
To: wikidata-l@lists.wikimedia.org
Subject: Re: [Wikidata-l] Page history and properties

I don't think, that the most claims are immutable.

Am Fr 05.04.2013 00:30, schrieb Michael Hale:
We will use qualifiers to tag values with dates for which they are relevant if there isn't a better place to put the information. We commonly use the example of historic population values. MediaWiki software saves disk space by delta encoding edit histories. http://en.wikipedia.org/wiki/Delta_encoding

I can probably think of at least 5 different ways we could arrange the schema of Wikidata to store information about US presidents, but I don't think using universal valid_from and valid_to values for every claim is the most efficient, natural, or flexible way to do so.

> Date: Fri, 5 Apr 2013 00:08:00 +0200
> From: benedix@zedat.fu-berlin.de
> To: wikidata-l@lists.wikimedia.org
> Subject: Re: [Wikidata-l] Page history and properties
>
> And what are you doing when you want the knowledge of the world from 5
> years ago? Isn't this a valid need? To compare what have changed for
> example in the measurement of ocean depth?
>
> These snapshots could be a low hanging fruit with valid_from and
> valid_to and it is saving disk space compared to storing complete dumps
> every day.
>
>
> Instead of having a "List of Presidents of the US" or looking up every
> person for a property "President of the USA" you could get this List
> from the property "President" from the Item "USA" together with
> valid_from and valid_to.
>
> Lukas
>
> Am Do 04.04.2013 22:23, schrieb Michael Hale:
> > I thought one of the main reasons we are making Wikidata is so that
> > you can update a value there, and then everywhere it is used will be
> > automatically updated. If we find a more precise measurement for the
> > depth of an ocean trench, then I just want to update it on Wikidata,
> > and then every article that references it will be updated. I don't
> > want to have to update it on Wikidata and then go do a null edit on
> > every article that uses that information.
>
>
> _______________________________________________
> Wikidata-l mailing list
> Wikidata-l@lists.wikimedia.org
> https://lists.wikimedia.org/mailman/listinfo/wikidata-l


_______________________________________________
Wikidata-l mailing list
Wikidata-l@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/wikidata-l


_______________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l


_______________________________________________
Wikidata-l mailing list
Wikidata-l@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/wikidata-l


_______________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l