[DDI-ADG] GeographicCoverage

[Katherine McNeill-Harman]

Here are my initial thoughts on this (and I won't be in the phone call 
Tuesday).  I think it's a helpful start, and particularly like your 
distinction between the type of level and the value within it.  Couple of 
comments/questions:

1) I like how you make GeographyValues present and required at each level 
of geography, but provide different ways to describe it.

2) I'm not sure I understand the relationship between GeographicCoverage, 
IntermediateGeography, and GeographicalUnit.  It appears that the latter 
two are sub-elements (if that's the right term) of the first, and within 
themselves would have multiple fields (some sort of nesting?).

I have mixed feelings about calling them three different categories; in my 
response to Sanda/Mary's email earlier, I wondered if we should have a 
single element for geographic level (and then maybe have its relationship 
with the others a sort of hierarchical characteristic).  I'm just trying to 
think about what'd be easiest for users and systems to interpret.  And 
conceptually, what is the difference between coverage and unit?  I know 
what the definitions are, but do we want to describe overall geographic 
coverage as the highest unit?

And then what do we do when we have several different types of geography 
but aren't exactly in hierarchical relationship with one another; how do we 
know which is the lowest unit (e.g. county vs. congressional district)?  I 
know it's nearly impossible to account for every possible scenario, but 
this one makes me wonder.

3) I wonder if we should require GeographicLevelName.  I like the idea of 
trying to see if there's a controlled vocabulary for GeographicLevelCode, 
to standardize among similar levels but with different names in different 
countries (e.g. province vs. state).  So let's say that the standardized 
term is sub-national (I'm just making that up); wouldn't we also want to 
provide users with a way of searching on the term used in that particular 
country (i.e. state)?  I know there's a balance between thoroughness and 
requiring too much, but it's a consideration.

4) Under GeographyValues, are we missing a place to link to an external URL 
w/the codes maintained by an external authority?

A lot of these are just ideas, and some of my comments are awkward to try 
to convey over email, but maybe it'll be material for your discussion Tuesday.

Kate

At 01:55 PM 6/30/2005 -0400, J Gager wrote:
>Hello Everyone -
>
>Attached is a general outline of what I had in mind for the Geographic
>Coverage after our discussion on Tuesday.  Note that I did not go into
>great detail about the specifics of any fields.  The point that I am
>trying to make is that it seems we need two types of identifcation for
>any geographic level:
>
>1.  The type of level we are describing - is it a countries, states,
>counties, cities, etc.
>2.  The possible values at that level - which may be described by code,
>coordinate, name, or reference a variable in the study.
>
>Feel free to comment via email.
>
>Thanks,
>
>J
>
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___________________________________________
Katherine McNeill-Harman
Data Services Librarian
Dewey Library for Management and Social Sciences
Massachusetts Institute of Technology
77 Massachusetts Avenue, E53-100
Cambridge, MA 02139
mcneillh at mit.edu
617-253-0787