Issue 390: scope note of E94 Space Primitive
Posted by Martin on 31/7/2018
The current scope note of E94 Space Primitive reads:
E94 Space Primitive
Subclass of: E59 Primitive Value
Scope Note: This class comprises instances of E59 Primitive Value for space that should be implemented with appropriate validation, precision and references to spatial coordinate systems to express geometries on or relative to earth, or any other stable constellations of matter, relevant to cultural and scientific documentation.
An E94 Space Primitive defines an E53 Place in the sense of a declarative place as elaborated in CRMgeo (Doerr and Hiebel 2013), which means that the identity of the place is derived from its geometric definition. This declarative place allows for the application of all place properties to relate phenomenal places to their approximations expressed with geometries.
Definitions of instances of E53 Place using different spatial reference systems always result in definitions of different instances of E53 place approximating each other.
Instances of E94 Space Primitive provide the ability to link CRM encoded data to the kinds of geometries used in maps or Geoinformation systems. They may be used for visualisation of the instances of E53 Place they define, in their geographic context and for computing topological relations between places based on these geometries.
Note that it is possible for a place to be defined by phenomena causal to it or other forms of identification rather than by an instance of E94 Space Primitive. In this case, this property must not be used for approximating the respective instance of E53 Place with an instance of E94 Space Primitive. E94 Space Primitive is not further elaborated upon within this model. Compatibility with OGC standards are recommended.
The last paragraph above talks about the property. This is wrong. I propose:
new last paragraph:
Note that it is possible for a place to be defined by phenomena causal to it, such as a settlement or a riverbed, or other forms of identification rather than by an instance of E94 Space Primitive. Any geometric approximation of such a place by an instance of E94 Space Primitive constitutes an instance of E53 Place in its own right, i.e., the approximating one. E94 Space Primitive is not further elaborated upon within this model. Compatibility with OGC standards are recommended.
Posted by Gerald Hieble on 1/8/2018
I do agree with the proposed new last paragraph of Martin, the current one should be substituted.
It is important that we make clear that geometries, preferably serialised using OGC standards as WKT or GML, are different places (with their identity derived through the geometry) to the phenomenal ones (with their identity derived through the phenomena), even if the geometries try to approximate a phenomena.
Posted by Richard Light on 1/8/2018
I agree with Martin's proposed rewording.
Posted by Steve on 1/8/2018
I think this is a good catch!
Posted by Christian Emil Ore on 1/8/2018
I agree, it is much clearer. One comment " .. its own right, i.e., the approximating one." May a word about what this one is approximating?
In the 42nd joined meeting of the CIDOC CRM SIG and ISO/TC46/SC4/WG9 and the 35th FRBR - CIDOC CRM Harmonization meeting, the crm-sig reviewed MD’s new scope note for E94 Space Primitive and agreed on it with minor revisions. Thus, the old and the new text of scope note can be found here.
The question how a Space Primitive, which under this definition is a literal, can also be a place (“This class comprises instances of E59 Primitive Value for space …” vs. “Any geometric approximation of such a place by an instance of E94 Space Primitive constitutes an instance of E53 Place in its own right”) was addressed by means of the E94 Space Primitive defines a place in the declarative sense, which in its turn approximates a phenomenal place. SS said that the last paragraph should be made more explicit in terms of declaring the path.
Berlin, November 2018