DDI Discovery Vocabulary

DDI Lifecycle – Moving Forward

21.10.2012 – 26.10.2012

Thomas Bosch

M.Sc. (TUM)postgraduate student

http://boschthomas.blogspot.comGESIS - Leibniz Institute for the Social Sciences

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Agenda

• Currently no such ontology available

• To increase visibility of data holdings using mainstream Web technologies

• To open DDI to the Linked Data community

• To process DDI-RDF by RDF tools

• To link DDI-RDF to other RDF data

• To better identify opportunities for merging datasets

• To enable inferencing

• To research microdata within the LOD cloud

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Why DDI as Linked Data?

• DDI subset • of the most important DDI elements

• Use cases• Experts in the statistics domain formulated use cases which are seen

as most significant to solve frequent problems

• Most important use case: discover microdata connected with multiple studies

• Leverage existing DDI-XML docs to DDI-RDF automatically• Direct mapping

• Generic mapping (Bosch and Mathiak, 2011)

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How was the DDI Ontology developed?

• Which studies are connected with a specific coverage consisting of the 3 dimensions: time, country, and subject?

• What questions with a specific question text are contained in the study questionnaire?

• What questions are connected with a concept with a specific label?

• What questions are combined with a variable with an associated coverage consisting of the 3 dimensions time, country, and subject?

• What concepts are linked to particular variables or questions?

• What representation does a specific variable have?

• What codes and what categories are part of this representation?

• What variable label does a variable with a particular variable name have?

• What‘s the maximum value of a certain variable?

• What are the absolute and relative frequencies of a specific code?

• What data files contain the entire dataset?

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Discovery Use Case

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study | coverage

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instrument | question | concept

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values | value labels

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variable | descriptive statistics

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logical dataset | dataset | data file

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conceptual model

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Thank you for your attention!

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