DDI Expert Committee Meeting

"Birds of a Feather" Meeting on Tools for the DDI
Ann Arbor, MI
May 24, 2006 (at IASSIST)

Meeting proposed by Joachim Wackerow;
Discussion chaired by Ron Nakao;
About 40 people in attendance;
Notes taken by Tom Piazza

Types of Tools Needed

  • Convert DDI version 2 to version 3

    With various options:
    - could convert instances 1-to-1 or 1-to-many modules
    - tool should help decide on choices
    - probably would be a set of XSLT sytlesheets
    - need example of the mapping

  • Convert DDI version 3 to version 2

    - would drop the new features
    - but would protect investment in version 2 applications

  • View a DDI version 3 instance, in a user-friendly way

    - reduce some of the verbosity, if desired (e.g., categories?)

  • Make a DDI version 3 instance

    - a form-driven system
    - would take care of the spelling of the tags
    - perhaps a DDI-aware editor

  • Make a DDI version 3 instrument document

    - must be built into the CAI system, for instruments of any size
    - Blaise and CASES seem willing to do this
    - MQDS system at Michigan currently makes version 2, but could make version 3

  • Make a DDI version 3 instance for pre-instrument steps

    - capture the beginning of the life cycle (e.g., from researchers and designers)
    - form-based entry for each step in the workflow

  • Combine several version 3 instances into a version 3 group

    - to take advantage of the new grouping functions

  • Convert a version 3 instance to data definitions for statistical packages (e.g., SPSS, SAS, or Stata)
  • Set up a forum to share tools

    - common stylesheets and programs

Tools Currently Being Worked On

  • Pascal Heus

    - Web site to upload version 3 examples and validate them
    - Viewer for those instances (convert them to HTML)
    - Develop an editor for version 3 on the Web (for small instances)
    - Help file for the version 3 schema (basically finished)

  • Joachim Wackerow

    - Convert SPSS and SAS system files to version 3 DDI
    - Convert version 3 into Docbook format (from meeting attendees)

  • Arofan Gregory and Mark Diggory

    - Migration tool for conversion between version 2 and version 3 (both ways) (may require user to make some choices or decisions)
    - Mapforce definitions, to lay out the conversion rules
    - SDMX registry tool that could be adapted for DDI

Resources Available

  • Primarily rely on volunteers (DDI participants)
  • Need some funding, however, to supplement and support that work
  • Could try to get vendors (like StatTransfer and SPSS) to adopt the DDI as a supported format

Next Steps

  • Set up a DDI tools Web page, for information and interaction
  • Set up a DDI tools working group and email list
  • Generate additional documentation for version 3
  • Generate many examples of version 3 instances

Addendum: Survey Results (From Meeting Attendees)

"Which statistical/data management software do you use?"

SPSS (25)
Stata (23)
SAS (20)
SDA (9)
Blaise (6)
R/S-Plus (6)
CSPro (2)
Statistica (0)

Other: PERL, ACCESS (2), Textpad (2), Oxygen (2), IPUMS, NHGIS, Eclipse (Microdata Management Toolkit), XMLSpy, Java, Ultra-edit, Visual Studio, Net2005