[DDI-users] a question about schemes/versions/references
Alerk Amin
A.Amin at uvt.nl
Fri Dec 17 05:33:04 EST 2010
Hello,
I've considered both of the options presented by Achim & Wendy. I
think some of Achim's alternatives sounds reasonable in theory, but I'm
having some trouble envisioning how they would work in practice.
Our (simplified) use case is that we could have a questionnaire with
100 questions. We may have 5 waves of questionnaires, and within each
wave, we might have 5 versions of the questionnaire (pre-test, pilot,
main-wave, follow-up, etc). In each of these questionnaire versions,
90% of the questions will probably stay the same (eg. "What is your
gender? 1. male 2. female" is probably the same for every version).
If we have copies of questions in different versions of the
QuestionScheme (such as Achim's Alternative #1 or #4), this would give
us 25 copies of the exact same gender question, each with a different
URN. If we estimate that 90% of the questions don't change out of 100
questions, this works out to 25*90 = 2250 QuestionItems when we really
only want 90. This seems extremely complicated for our survey
designers, as well as our disseminators.
I'm not sure how Grouping or Resource Packages would resolve this
problem, because we will still end up with different versions of the
QuestionScheme, as the questions change from version to version.
Wendy's solution (which I think is the same as Achim's alternative
#2) seems to avoid the duplication problem, but I am curious how it will
work with respect to References. In Wave 2 of the questionnaire, we'd
ideally like all the QuestionConstructs to reference items in version
2.* of the QuestionScheme. But by including qs v1.0.0 in qs v2.0.0 as
described by Wendy, how will a reference such as
urn:ddi:agency:QuestionScheme.qs.2.0.0:QuestionItem.qA.L get resolved?
Thank you again for all of your help.
Best,
Alerk
On 12/16/2010 3:44 PM, Wendy Thomas wrote:
> 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
>> Visiting address: B2 1, 68159 Mannheim, Germany
>> Postal address: P.O. Box 122155, 68072 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/
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>>
>
> 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
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