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

[Wendy Thomas]

Alerk

This can actually be handled well by how you construct the new version of 
your maintainable.

qs v2.0.0
    qs v1.0.0 except qC
    qC v2.0.0



In this way the qA v.1.0.0 continues to live within qs v1.0.0

This was a deep bar napkin discussion at an outside table at the Town Hall 
Brewery clearly during better weather than we have now.

Wendy


On Thu, 16 Dec 2010, Joachim Wackerow wrote:

> Hi Alerk,
>
> This understanding is correct. A new version of qC triggers a new
> version of the question scheme. Then you have basically two identical
> objects with none-identical identifiers.
>
> You can use different approaches to solve the issue:
>
> Alternative 1:
> The QuestionItem for qA and qB can mention the objectSource, which is a
> reference to the object from which the item is being copied.
> http://www.ddialliance.org/sites/default/files/documentation/ddi3.1/schemas/reusable_xsd/complexTypes/AbstractIdentifiableType.html#r5
>
> Alternative 2:
> qs v2.0.0 could reference qA and qB in qs v1.0.0 where they live.
>
> Alternative 3:
> qA and qB could live in a resource package where they can be referenced
> by wave 1 and 2.
>
> Alternative 4:
> It is possible to state in the comparison module that two questions
> (here identical, but with different identifiers) are the same
>
> Alternative 5:
> With the grouping approach it is possible to push everything, which is a
> candidate for reuse, to a higher level. Then no replication of objects
> takes place.
>
> Dependent from the background one of this solutions is preferable to the
> others. As far as I understand alternative 1 and 3 seem to be good
> candidates. They are not too hard to implement.
>
> Cheers,
> Achim
>
> Alerk Amin wrote:
>> 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
>>
>
>
> -- 
> GESIS - Leibniz Institute for the Social Sciences
> Department: Monitoring Society and Social Change
> Unit: Social Science Metadata Standards
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