Wikidata:WikiProject Geodata/Data structure
On Wikidata, any property should be associated with several statements. If you are considering extracting geodata from this website, you should be able to cope with this situation.
Wikidata statements, can be associated with qualifiers that define more precisely their meaning. Here a some of those you are likely to encounter in Property:P625. Please be aware that these are not strict rules that are guaranteed to be followed. It is strongly recommended that you allow for some flexibility in you extraction tool.
applies to part (P518)
A large item such as a city or a river is best represented by a geoshape rather than a single coordinate. Coordinates can however also be useful for these but you should use this qualifier to indicate the point of the object to which the coordinates are referring. Here are some possible values:
| value | domain | meaning |
|---|---|---|
| midpoint (Q1645406) | any object with a line-like shape | Point that is equidistant from both ends, when following the object (for example kilometer 200 on a 400 km road) |
| beginning (Q15053706) | any object with a line-like shape and a direction | for example the point of the road with house number 1 or with kilometer 0 |
| end (Q15053716) | any object with a line-like shape | the end point of a directed line or either extremities of an undirected line |
| spring (Q124714) | river | point where the river appears (Q15053716 might also be used) |
| river mouth (Q1233637) | river | point where the river flows into another one, or into a lake or sea |
| kilometre zero (Q329477) | most likely an administrative unit | point from which distances are computed |
| center of gravity (Q114084) | any surface | |
| station building (Q1339195) | train station | sometimes used as the coordinates of a train station in Wikipedia |
| railway track (Q284101) | train station | used as main coordinates of a train station in fr.wikipedia |
point in time (P585)
For something that is moving (slowly), such as the North Magnetic Pole (Q842763). Use this qualifier to note when the coordinates were accurate.
start time (P580), end time (P582)
Use for something which was in one location and was then moved to another location. e.g. fontaine du Château d'eau (Q3076267).
determination method or standard (P459)
How the measure was made.
- Especially relevant when the coordinates provided are very precise but not necessarily easy to express in Wikidata-format. See Q2467833
- Should we say "determination method: Google maps" to mean we have looked at the coordinates on a Google map sattelite image ("source: Google maps" does not seem accurate if Google does not provide the coordinates explicitly). --Zolo (talk) 20:58, 9 October 2013 (UTC)
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