[DDI-SRG] Bug 106

[Wendy Thomas]

The following proposed solution plus a note from the wikipedia definitions 
of claasisfication levels that discuss continuous and discrete. This bug 
was originally files by Pascal. It will be on the agenda Thursday unless 
we can agree on this over email.  wlt

ADD the following attribute to RepresentationType so that it is inherited 
by all the possible Representation types listed in DDI:

ClassificationLevel  0..1  type="CategoryRelationCodeType"

ClassificationLevelCode  xs:string
restrictions:

nominal =	The categories in the domain have no greater than or less 
than relationship between them. (sometimes called categorical or discrete)
ordinal =	The categories in the domain have a rank order
interval =	The categories in the domain are in rank order and have a 
consistant interval between each category so that differences between 
arbitrary pairs of measurements can be meaningfully compared.


The following two values could be added to CategoryRelationCodeType (along 
with the above definitions) to provide a broader set

ratio =		The categories have all the features of interval 
measurement and also have meaningful ratios between arbitrary pairs of 
numbers.
continuous =	A grouping of interval and ratio classification levels to 
be used when more defininitive information is not available.





Wendy L. Thomas                          Phone: +1 612.624.4389
Data Access Core Director		 Fax:   +1 612.626.8375
Minnesota Population Center              Email: wlt at pop.umn.edu
University of Minnesota
50 Willey Hall
225 19th Avenue South
Minneapolis, MN 55455