[DDI-SRG] Variables, questions and qeustionnaire

[Pascal Heus]

All:
Was thinking about the variable/questionnaire relationship this morning
and we may have a problem in the schema as we can define a link between
a question and a variable (using  Variable/QuestionReference) but I
don't think we can related the variable to the survey instrument itself
(like the ControlConstruct and the actual location in an Instrument).
This is important when I serialize a file (actually collect and store
data) as it is typically then tied to a specific Instrument
(questionnaire). If I reuse a question in multiple ControlContruct and
then insert that in Instrument(s) (one or more time), how do I know
which actual question in my instrument the variable in my data file
refers to? I don't think this is possible in 3.0.

Use case: a simple household survey:
- Define question Q1: "how old is [NAME]"
- Define variable V1: age  that refers to Q1
- Define two constructs that use Q1
   - CC1 used in the demographics module, question is asked to head of
household)
   - CC2 , used in the children under 16 questionnaire (asked to the kids)
- Define Instrument I1 that uses CC1 and CC2 (and/or make case more
complex by creating more than one instrument)
- When I actually produce data for that instrument where I reuse the age
variable V1, it can come from two different places and I do not know
which one

(1) Is this really a problem (or did I miss somtehing)?
(2) If yes, I think this could be resolved at the LogicalRecord or
Variable (maybe by refining the Question reference or adding reference
to the CC and/or Instrument) [need some thinking]

Note that if I create two age variables, the problem remains as I don't
know which CC / instrument it refers to

*P