[DDI-SRG] EduDDI in Germany

[Joachim Wackerow]

Yesterday I was at the second meeting of EduDDI and some good news:

EduDDI was formed last December to build a framework for using DDI3 at 
several educational research institutes in Germany. The driving people 
are Michel Knigge und Martin Mechtel from the IQB in Berlin (Institute 
for Educational Progress), who attended the workshop last autumn in 
Dagstuhl. One other important institute is the DIPF (German Institute 
for International Educational Research). One goal is to build resource 
packages specific for the needs of educational research.

It was mentioned that NEPS is planning to use DDI3. The National 
Educational Panel Study (NEPS) is a new major panel study in Germany.
http://www.uni-bamberg.de/en/neps/

A student is working in the Diplomarbeit (like master thesis) on the 
subject standards/DDI.


Some questions/issues were raised at the meeting:


- Test scales

The data collection module does not cover enough the needs for test 
scales. Example: tasks of the PISA study. IQB would be interested to 
discuss this requirement after some further experiences with DDI.


- Controlled vocabularies/Genericode

They are interested to use Genericode lists in an extensive way. Not all 
places in DDI3 - they are interested - in support this possibility. In 
generalizing this approach: I think it would be a good idea to support 
the mechanism of adding a Genericode list to every machine-actionable 
string value of elements/attributes. This way specific allowed values 
can be defined in a flexible way dependent from the 
institution/domain/application. As already discussed and in development: 
the DDI Alliance can publish Genericode lists (controlled vocabularies) 
for some elements where a general, domain-independent CV can make sense.

This would cause a change on every element/attribute which is defined as 
xs:string and probably additionally elements/attributes which are 
defined as InternationalStringType, TypedStringType, and OneCharStringType.


- Universe, machine-actionable value

They asked also for a way to use values - which are mentioned in 
CodeSchemes/CategorySchemes - in Code of Universe.
Example: a survey on all German Bundeslaender has a variable Bundesland 
with a related CodeScheme/CategoryScheme. In further surveys specific to 
only one Bundesland the Universe should be defined (and controlled) 
according to the CodeScheme/CategoryScheme of the other survey.

Universe in conceptual component has a child MachineReadable ("A 
machine-readable statement of the universe, expressed as a Coding."), 
which is defined as r:CodeType ("Structures the expression of a coding 
in the data collection process."). This element is used several times in 
data collection, where it does make sense. There seems to be something 
weird. The attribute programmingLanguage does not really make sense for 
a universe.

If MachineReadable would be defined as l:CodeType, then it would meed 
the above mentioned requirement. Was this the original intention?

Anyway, this issue seems to need some discussion.


- Universe of a variable, which is defined in a resource package.

Reusable variables should stay in resource packages. When using this 
variables from a VariableScheme by VariableReference it doesn't seems to 
be possible to define a specific universe. This is only possible below 
Variable in the resource packages, where it doesn't make sense, because 
the variable should be reusable, i.e. reusable for different universes. 
Currently a workaround with VariableGroup is possible. VariableGroup can 
have a UniverseReference and can use VariableReference to point to the 
Variable in the resource package.

It seems that UniverseReference (now used in Variable) should also be 
also usable in VariableReference and VariableGroupReference.


Achim


-- 
GESIS - Leibniz Institute for the Social Sciences
Postal address: P.O. Box 122155, 68072 Mannheim, Germany
Visiting address: B2 1, 68159 Mannheim, Germany
Phone: +49 (0)621 1246 262
Fax: +49 (0)621 1246 100
E-mail: joachim.wackerow at gesis.org
www.gesis.org/en/institute/