[DDI-users] a question about schemes/versions/references

[Alerk Amin]

Hello,

   I have a question regarding schemes, versioning and references.  The 
following is a simplified version of a real use case that we have.

   Suppose we have a QuestionScheme qs, which has 3 questions qA, qB, 
qC.  At the beginning (wave1 for example), we have

qs v1.0.0
	qA v1.0.0
	qB v1.0.0
	qC v1.0.0

At this point in time, its clear that any QuestionConstructs or 
Variables that reference these questions would use
urn:ddi:agency:QuestionScheme.qs.1.0.0:QuestionItem.qA.1.0.0
  or something similar (I might not have the exact syntax correct).

Now, my question comes up when we move to wave 2.  Suppose qA and qB 
remain the same, but we change qC.  Now, we have

qs v2.0.0
	qA v1.0.0
	qB v1.0.0
	qC v2.0.0

Now, a reference to qA would be
urn:ddi:agency:QuestionScheme.qs.2.0.0:QuestionItem.qA.1.0.0
   Even though the question has not changed, we have a different version 
for the QuestionScheme, and therefore a different identifier for the 
QuestionItem.  If we have two different variables for the 2 different 
waves, they would have different QuestionItemReferences, and therefore 
it becomes impossible to determine that they are based on the same question.

   Is my understanding of this correct?  If so, doesn't this hurt the 
reusability of items?
   Thank you for your help.

Best,
Alerk

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Alerk Amin M.Eng.
Senior Software Developer
CentERdata
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