Hoi,
It is certainly one way to exclude many people who might be interested.
Thanks,
GerardM
On 20 September 2015 at 20:08, Daniel Kinzler <daniel.kinzler(a)wikimedia.de>
wrote:
I replied at
https://phabricator.wikimedia.org/T105623. Lets keep the
discussion
there.
Am 19.09.2015 um 21:14 schrieb Michael Peel:
> On 19 Sep 2015, at 19:16, Daniel Kinzler <daniel.kinzler(a)wikimedia.de>
wrote:
>
> Am 19.09.2015 um 10:27 schrieb Egon Willighagen:
>>
>>
>> On Tue, Sep 15, 2015 at 10:12 PM, Michael Peel <email(a)mikepeel.net
>> <mailto:email@mikepeel.net>> wrote:
>>
>> It seems to assume a default uncertainty on values, though: I just
added the
>> elevation above sea level to:
>>
https://www.wikidata.org/wiki/Q1513315
>> just specifying the central value, and it assumes that this value
is +-
0.1
>> km - which isn't a good assumption
to make...
>>
>>
>> Did you mean to write 2.80 km about sea level? Then the error would be
0.01 km
>> .... I am guessing the uncertainty
follows the scientific notation of
the
>> number... 2.8 has the numeric uncertainty
of (about) +/- 0.1...
>>
>> That sounds like a reasonable approach to me...
>
> Yes, the uncertainty follows the scientific convention about
significant
digits.
Taking that approach is a *really* bad idea. You can't just assume/make
up
uncertainties!
As an example, say you have a length of 100m. Which significant digit do
you
assume is correct? Is this +- 100m, 10m or 1m? What if it's referring
to the length of a 100m run, where the accuracy could be much higher than
the significant digit given, e.g. 100m +- 1cm? Or what if it's the size of
a crater on a distant planet, where it might be 100m+-50m? Or if the actual
value is 100m +- 3m, but we say that it's +- 1m (which I see is the default
in this case), which might be believable to readers but very misleading in
reality?
We are currently thinking about adjusting this a
bit, see
https://phabricator.wikimedia.org/T105623
As thiemowmde says there:
"The fact that the parser "guesses" a precision based on basically zero
information always was and still is wrong. It must default to ±0.
Everything else is misleading and a source of significant confusion and
actual errors."
... although perhaps a better approach if
possible might be to default
to -1, or something else indicating the absence of
data.
Thanks,
Mike
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Daniel Kinzler
Senior Software Developer
Wikimedia Deutschland
Gesellschaft zur Förderung Freien Wissens e.V.
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