15th European DDI Users Conference, Ljubljana

DDI-Lifecycle utilises the variable cascade to organise and describe data from conception to collection.
The organisation of conceptual variables and conceptual variable groups allows comparison of data at different time points, universes, representations and many other dimensions through concordance tables and is well suited to iterative data collected as panels, cohorts, repeated surveys...

A value domain is the description of the values a variable is allowed to take. The idea originated with the ISO/IEC 11179 series of standards. DDI-CDI makes use of them explicitly, and DDI-L uses the idea as well. However, metadata reuse depends on which metadata are assigned to a variable, and which are assigned to a value domain. We address this here.

We can illustrate the problem with an...

Mixed mode surveys are not new but have become quite popular or necessary recently due to a variety of reasons such as enhanced response rates, access to diverse populations or flexibility.
When it comes to creation, documentation, or management of mixed-mode survey they become complex to handle, then having one master questionnaire. More complexity is followed by more resources, making...