Generating Blaise from DDI Gerrit de Bolster September
Generating Blaise from DDI Gerrit de Bolster September 24, 2013
What is DDI? v On the web page of the DDI Alliance the following definition is found: “The Data Documentation Initiative (DDI) is an effort to create an international standard for describing data from the social, behavioural, and economic sciences. ” v From Wikipedia, the free encyclopedia: “The DDI is an international project to create a standard for information describing statistical and social science data (i. e. , metadata). The DDI specification, written in XML, provides a format for content, exchange, and preservation of information. ” 2
Where is DDI used? Gerrit 3
Why should we use DDI? v DDI is an open standard expressed in the global supported standard XML v Since version 3 the concept of a data collection instrument was introduced v Using DDI for defining a data collection instrument opens the way for other organisations (including commercial software vendors) to create solutions v Instrument definitions can be re-used by other organisations 4
DDI fits in a “plug and play” architecture POC 5
The Proof Of Concept v. Create a DDI definition for an instrument § samples available: MQDS, QDT, Colectica, ddialliance. org v. Use an existing generator (BLS-Wizard) § add a converter: DDI definition to generator input file § output: Blaise. IS 4. 8 CAWI instrument v Create a set of working samples § questionnaire, form, download portal, upload portal 6
A lot of references… Demo 7
DDI alone is not enough! Technical additions in the POC: v Templates (including basic Menu file, adapted ASP’s/XSLT’s) v Layout definitions (Mode Library -> CSS) v Type & procedure libraries v Lookup data (in the POC a definition in DDI was created) v Etc. What should/could be included in DDI? Do we still speak a little bit Blaise language or include other standards (e. g. Math. ML, CSS)? 8
DDI instance: Instrument or Blaise? v DDI is not a programming language v The Blaise source language is very rich What is the added value to create a DDI definition for the Blaise source language instead of using Blaise? v DDI aims at supporting a generic meta definition for datacollection instruments Create a generic meta definition for datacollection instruments, not another source language! 9
Lessons learned v DDI is a very open standard. A standard DDI instrument definition is a prerequisite for a successful use in the Blaise community. v DDI is not human readable. An Instrument Design Tool with a repository is a must! v DDI should be a stable open standard, upward compatible. The schemas of a later version (3. 2) should still support a definition in an earlier version (3. 1). 10
DDI Tooling: what’s next? v A Blaise community working group? v A commercial product? v No action at all? I'm open for discussion! Any questions? Or answers? 11
Thank you for your attention! 12
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