For "special" precision in Wikidata interface, show dimension in meters
Open, NormalPublic

Description

When you look at the coördinate claim at https://www.wikidata.org/wiki/Q9365381 and you'll open it in the editor you'll see:
50°4'51"N, 18°12'3"E special (±0.014000802722428°). This special is because it's the converted dimension in meters (https://www.mediawiki.org/wiki/Extension:GeoData#Glossary). The user interface should for special values calculate this dimension in meters and show that to the user instead.

Multichill updated the task description. (Show Details)
Multichill raised the priority of this task from to Needs Triage.
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptFeb 11 2015, 7:31 AM
Lydia_Pintscher triaged this task as Normal priority.Feb 16 2015, 5:14 PM
Lydia_Pintscher added a project: Wikidata.
Lydia_Pintscher set Security to None.

The actual conversion code in Pywikibot is at https://git.wikimedia.org/blob/pywikibot%2Fcore.git/HEAD/pywikibot%2F__init__.py#L292

Reminded me to file a task to also implement the other way around (https://phabricator.wikimedia.org/T89670)

Converting that to meters is not possible without taking the latitude into account (which is what pywikibot correctly does). Which means, the same precision value (stored in degrees and displayed in meters) will be displayed different on different locations. The precision will even "magically change" when you edit the latitude, but not the precision.

Our GeoCoordinateValue is defined with a precision in degrees, not meters. We may discuss this decision, if necessary. But as long as it's degrees, I think it's better to display degrees and not do possibly confusing conversions.

I suggest to close this as wontfix.

Converting that to meters is not possible without taking the latitude into account (which is what pywikibot correctly does). Which means, the same precision value (stored in degrees and displayed in meters) will be displayed different on different locations. The precision will even "magically change" when you edit the latitude, but not the precision.

Our GeoCoordinateValue is defined with a precision in degrees, not meters. We may discuss this decision, if necessary. But as long as it's degrees, I think it's better to display degrees and not do possibly confusing conversions.

And a precision of ±0.014000802722428° is not confusing? If the interface would say ±0.014000802722428° (about 10 meters), that would be a lot clearer

I suggest to close this as wontfix.

I don't agree with that.

+/-0.014000802722428° is something between 0 and 1555.644746936 meters. How is that helpful?

+/-0.014000802722428° is something between 0 and 1555.644746936 meters. How is that helpful?

I agree not doing the calculation is not useful at all. You should do the calculation based on 50°4'51"N, 18°12'3"E so you know how many meters it is.

Jc3s5h added a subscriber: Jc3s5h.EditedJul 6 2015, 10:38 PM

The dimension of an object is different than the precision. The horizontal dimensions of the [[en:Middlebury to Her Soldiers (sculpture)]] monument appears to be about 3 m. But if I were the one who had to measure the location, my recreation-grade GPS unit would only be accurate to about a 30 m radius. So precision should be separate from horizontal size, and we should not conflate them. When precision is understood as the uncertainty in measuring latitude and longitude, it makes perfect sense that the uncertainty in the location of the monument is ±0.0001° (about 11 m in the north-south direction or 8 m in the east-west direction). Of course, since there is only one value available for precision, the editor who enters it will have to determine the greatest angular uncertainty, depending on the method for finding the position, and enter it.

Congratulations on the development team for displaying the unit of measure, degrees, for the precision in the user interface.

Jc3s5h added a comment.Jul 8 2015, 9:56 PM

I have added this to "Lack of geographic shape data type causing trouble" on the data model talk page, since there seems to be disagreement about the conceptual meaning of the precision of a latitude or longitude.