[DDI-SRG] Questions

[Wendy Thomas]

Back from Nairobi and lack of connection and band width. See answers 
below:

On Sun, 29 Mar 2009, Pascal Heus wrote:

> All:
>
> during conversations with the Canadian RDC network, the following
> questions came up. Can you help/clarify?
>

> - How do you attach a universe to a Cube? (may be different from variables)
UniverseReference in Variable is optional. Not used for variables 
expressing NCube dimensions. NCube also has a UnvierseReference which is 
where you attach its universe.

>
> - Can you subset a cube on a variable that is not one of its dimension?
>
No, but you can designate a set of variables on a record that are treated 
like selection variables. For example all of my DDI 2 nCubes (you have 
copies). This designates a record as a case for a single geographic or 
otherwise defined aggregated population area/definition. Each record 
contains a set of NCubes for that case. This allows you to define each 
data item location by its position in the record and not have to repeat 
everything for the case dimension.


> Given the constraint of 1 concept / variable
> -    How can you use multiple concept banks (when mappings may not exist)?
>
you map them OR you use VariableGroup which also has a link to Concept 
thereby allowing you to link those variables to another list of concepts. 
Personally it would probably be faster to map the comparison if you have 
lots of concept lists.


> -    One concept by design, many after the fact: how can user attach new
> concepts to a variable?
>       - example: Design: Risk behavior /  After the fact: Fertility,
> STD, etc.

See above

Wendy
>
> thanks
>
>
>
>
>
> _______________________________________________
> DDI-SRG mailing list
> DDI-SRG at icpsr.umich.edu
> http://www.icpsr.umich.edu/mailman/listinfo/ddi-srg
>

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