[DDI-SRG] Bug resolutions

[Wendy Thomas]

Here are the discussion notes and resolutions for bugs assigned to J. 
Please review and enter any additional discussion in Mantis.   wlt

0000027: Need a Represenation for "system missing" data
Description  QUESTION: How do I deal with "system missings"? There is a 
category label - INAP. But no code (in the data file, it's just empty 
spaces) And I do have statistics for them.
Proposed Solution  ANSWER: I will put in a bug on this, but here is a 
means of handling it in
the current structure.

Create a variable with the appropriate label. In VariableDefinition
indicate that this is an inapplicable variable and is represented by
blanks in the data set. You are not required to provide a Representation.
In the physicaldataproduct simply indicate the number of characters. As
for statistics, you don't have to do statistics for anything you don't
want to. Skip this one.

Should there be a specific Represenatation for these kind of "empty" 
variables? They exist in the data

Related Module  Logical
XPath  Variable/Representation

RESPONSE:
Variable regardless of type should allow specification of one or more 
"missing value"
Do we want a default missing value statement? where would this go?
Add a "blank" content type
"Not a number value"
string types tag


0000029
Summary  0000029: Content of Numeric Representation does not cover all 
needed options
Description  NumericRepresentation needs to contain the following:

CHOICE (0..n)
Inclusive Range: LowerValue (with inclusive boolean att)
                  UpperValue (with inclusive boolean att)
Exclusive Range: same as above

Topcode (value)
Bottomcode (value) [for center point anchors]

I think the decimal information current buried in the current range 
information as well as measurement unit are both repeated in the Variable 
information in general. This needs to be thoroughly reviewed.
Proposed Solution
Related Module  Reusable
XPath  NumericRepresentationType

Also need to be able to identify "missing value" for example range 1 - 10, 
missing is 99. In category variables this is handled by the inclusion of a 
code and category label. We need this for other types of contents.

RESPONSE:
Add specified content. See 0000027 for missing value issue


0000032: ComputationItem's AssignedVariableReference should be optional
Description  The ID working group decided that not all information present 
in an instrument could be captured in the Schema in time for DDI 3.0, but 
we still wanted a place to add in variable assignments, external calls, 
check statements, etc. ComputationItem was created as a "catch all" for 
things that are currently not described in the DataCollection schema.

An optional assignedVariable was added to the ID UML model to help in the 
case of describing an assignment statement.
Proposed Solution  Change AssignedVariableReference to include 
minOccurs="0" in ComputationItemType

<xs:element ref="AssignedVariableReference" minOccurs="0">
   <xs:annotation>
     <xs:documentation>A reference to a variable to which the associated 
value in the Code element is assigned.</xs:documentation>
     </xs:annotation>
</xs:element>

Related Module  DataCollection

In looking back at the orignal UML diagram this was identified as a 0..1 
and was misentered in the original version of 3.0. This was perpetuated in 
subsequent versions. There are cases where no assigned variable reference 
is needed and this should be changed to minimum=0 as stated in the 
originally proposed model


RESPONSE:
Make optional



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
University of Minnesota
50 Willey Hall
225 19th Avenue South
Minneapolis, MN 55455