More UCR comments

Dear Frans, Alejandro, all,

a few comments on the current draft - mainly from the background of the use case I have contributed. I understand that this will likely be too late for the current version, but hope that we can discuss them when we prepare the next version. If I should add them as issues or pull requests let me know. I have lost overview what the correct process is for which type of comment...


Requirement 5.20 (linkability) states: "Spatial data on the Web should be linkable (by explicit relationships between different facts in different data sets), to other spatial data and to or from other types of data."

I did not find "fact" in the glossary. On the other hand it has "feature" and that is used in other requirements, too. I would therefore propose to change "facts" to "features".

Linkability is also relevant for links within a data set. I would therefore propose to change "different data sets" to "the same or different data sets".

The use case 4.10 (publishing geospatial reference data) also discusses the need for a capability to establish implicit links by identifying properties in features that are typical candidates for joins. To reflect this I would propose to introduce another requirement like "Spatial data on the Web should identify the semantics of feature properties in a common way to enable joining other types of data with the spatial data. Note: The purpose of these joins is typically to georeference the other data."

Another aspect of use case 4.10 is that it should be possible to determine the spatial relation between features in different data sets. Req 5.45 (spatial operators) may address this - in which case it should be linked to 4.10. However, it is not entirely clear what "operators" are in this context. Is the idea that any API providing access to a spatial data set provides these spatial operators so that I can determine, for example, all spatial things in the dataset that 'intersect' in another data set? If yes, should this be made explicit, perhaps in a note?

Finally, the requirement text of 5.56 is the same as in 5.55. This must be a copy&paste error.

Thanks,
Clemens