1. A Gentle Introduction to DDI - What's in it for me? Jim Jacobs University of California, San Diego Wendy Thomas University of Minnesota

3. List of handouts Module description DDI track Guide to sourceforge List of websites and documents List of people, e-mails

4. Quick Review: HTML / XML stuff

5. Quick Review: HTML / XML The Sun Also Rises

6. Quick Review: HTML / XML The Sun Also Rises

7. Quick Review: HTML / XML The Sun Also Rises

8. Quick Review: HTML / XML The Sun Also Rises HTML documents can impart appearance. XML documents impart meaning.

9. Quick Review: HTML / XML But… where are the rules for and ?? Why not or ? What do we use?

10. Quick Review: HTML / XML But… where are the rules for and ?? Why not or ? What do we use? The vocabulary and syntax are defined in a special document. There are two kinds of these special documents: Document Type Definition (DTD) Schema

11. Quick Review: HTML / XML HTML is defined in a DTD: http://www.w3.org/TR/html4/sgml/dtd.html <!ENTITY % fontstyle "TT | I | B | BIG | SMALL">

12. DDI DDI 1 and 2 were defined by a DTD http://www.icpsr.umich.edu/DDI/Version2-1.dtd DDI 3 is defined by a Schema http://cvs.sourceforge.net/viewcvs.py/*checkout*/ddi-alliance /ddi/w3c/Version2-1.xsd

13. DTDs and Schemas HTML document HTML DTD HTML document

14. DTDs and Schemas DDI 2 document DDI 2 DTD DDI 2 document

15. DTDs and Schemas DDI 2 document DDI 2 DTD DDI 2 document DDI 3.0 Document DDI 3.0 Schema DDI 3.0 Document

16. What is the advantage of Schema over DTD? XML as a document format XML as a data format DTDs are more useful for describing XML document formats Schemas are more useful for describing XML data formats.

17. What is the advantage of Schema over DTD? Despite the intentions of XML's inventors, who mostly envisioned XML as a format for web pages and other narrative documents to be read by people, the most common applications of XML today involve the storage and transmission of information for use by different software applications and systems. -- XML in a Nutshell, Elliotte Rusty and W. Scott Means

18. What is the advantage of Schema over DTD? Schemas make it easier to treat metadata like data. The focus becomes on the content (e.g., the variables, questions, question groups, concepts, etc.), not the application (e.g. SAS, SPSS, PDF…).

19. A little vocabulary… Elements Attributes

20. A little vocabulary… Elements Attributes

21. A little vocabulary… Data types –string –decimal –integer –boolean –date –time

22. A little vocabulary… Namespace A means of distinguishing between elements and attributes from different XML vocabularies that have the same name. Apples Bananas African Coffee Table 80 120

23. A little vocabulary… Namespace A means of distinguishing between elements and attributes from different XML vocabularies that have the same name. Apples Bananas African Coffee Table 80 120

24. What are the advantages of Schema over DTD? Written in XML Support for data types Support for namespaces Better control over information (e.g., minimum and maxium values) Support for XML as a data format Modularity Machine-Actionable

25. So… what can we do with DDI 3.0? Better manage our local archives with the Archive Module. Better manage different (and multiple) physical formats and/or record subsets. Transform information from XML into rss, rdf, pdf, html, xml, SPSS, etc. Record information on the lifecycle of research [versioning information]