[DDI-SRG] Missing value range and interval measurement

[Joachim Wackerow]

Currently I'm working again on the SPSS converter.

I'm wondering how to express in DDI a missing value range of a variable 
with an interval measurement level.

For example the variable temperature. A missing value range is 20-25 
Celsius. The values are expressed as floating numbers like 20.17 etc., 
which are not all known in advance. This can be expressed in SPSS. In 
DDI I don't see a way. Do I miss something?

For variables with ordinal measurement (i.e. with categories like 
occupation) a workaround can be used for expressing a missing value 
range in DDI. Each category in the missing value range must be defined 
as missing. This can produce some overhead. Category entries with just 
the missing definition can be produced without labels depending on the 
definition in files of the statistical packages.

Any ideas? I think we discussed already a similar issue?

Achim