[Data-modeling] Location question

[Ed Laurent]

>
> I don't dispute that: the issue is that "Northwestern States" denotes
> a concept which itself is associated with different sets of states,
> depending on who is doing the defining — and unlike 'official'
> definitions, nobody is right or wrong.


I'll reference Issue 3 and my intiial "Spruce-fir forest" example again. We
can model a location category/concept and link it with defined locations
that fall in that, and possibly other, categories. Defined locations can in
turn be linked to the sources that define them (preferably a map metadata
topic).


I think that union implies an exclusive set of parts, whilst
> containment does not. I agree that the point is kinda moot without
> transitive queries, but with them it would be good to take union down
> to whatever level of granularity seems valid — it's probably fine to
> have countries, states, counties, and even parcels or neighborhoods be
> defined as unions of the next smaller thing, with cities and towns
> etc. being contained by the smallest thing that can contain them
> entirely.



The way I defined "Location union" in the Enhanced location base is "A type
for describing the location of topics as occurring within the combined area
of two or more other locations but not completely contained by either
location individually." The reason I defined it this way was because I
interpret the "Contains" and "Contained by" properties of "Location" as a
phylogeny that defines the exclusive (nested) set you described above. It's
definitely not being used this way, but that's a result of the coarse model
IMO.

My purpose for "Location union" was to describe relationships among
locations of different themes. For example, which states, in combination,
contain an ecoregion? Perhaps this is what you meant by "containment"?

-Ed
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freebase.com/pipermail/data-modeling/attachments/20090713/97e3d3cd/attachment-0001.htm