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UI Expand
titleVirtual Meeting 17 June

Attendees: Jay, Larry, Jannik, Johan, Oliver, Wendy Jon, Thérèse



The Agent, Process, Conceptual parts of the library and the discovery view were created in Drupal during the Toronto sprint. They are now ready to be reviewed by the modelling team. There are notes on the wiki which should help you to know what needs to be checked in Drupal and what conventions have been agreed (see: Drupal Conventions). Wendy will review this document to make sure that it is up to date and correct.

The review works was allocated out as follows:

  • Agent = Oliver
  • Process = Jannik
  • Conceptual = Jay
  • Discovery = Larry

Jon will look at everything from a documentation rather than modelling perspective. Johan will go on holiday (tongue)

The group agreed to meeting in 2 - 3 weeks to discuss results of the reviewing work.


UI Expand
titleTC Meeting 31 July regarding modeling

DDI TC Meeting Minutes

In Attendance: Wendy Thomas (organizer), Dan Gillman, Jay Greenfield, Larry Hoyle, Flavio Rizzolo, Achim Wackerow

Secretary: Elise Dunham


Moving forward: grouping mechanisms


-Revisit documentation & work done on pulling together use cases around groups of study units and different ways of grouping study units. Start a thought piece and send around so others can review and add on.
-Assist Achim with DDI -> 11404 & Smalltalk mapping if needed.

-Look at existing groups types in DDI 3 and experiment with mapping to ISO 11404 and Smalltalk.

-Send out any thoughts/musings on grouping mechanisms over the next week.



-Jay sent a document highlighting the importance of de-coupling data models from bindings/encodings. There’s agreement that the grouping mechanisms discussion needs to happen from the modeling perspective rather than the binding; doing bindings is something that should happen independently of the modeling work.
-It’s important for us to be aware of the struggle associated with transitioning from XML to UML—when modeling from an XML perspective binding and modeling happened together, but now, in UML separating them is one of our design criteria.

Abstract Bag

-Need to agree on the features of the bag and need to come up with extensions on that for specific types of collection purposes.
-In order to frame this discussion and bring it from the abstract to something practical, Achim volunteered to map group types on DDI 3 to 11404 and SmallTalk.
-"Why are we grouping things?" needs to be one of the driving questions framing this discussion
and informing decisions.

Level of Extensibility
-How do we limit application of these grouping mechanisms to prevent creation of groups that shouldn’t be created? Ex: ResponseDomain and CodeList don’t need groups around them. Is it possible to identify a limited set of groups, or is it not feasible to identify all of the use cases? Should we leave the opportunity to use a group for a purpose that is currently unknown?
-Achim’s mapping will help frame the discussion on striking this balance.

Challenges of UML -> Relational Mapping

-The conceptual constructs we’ve been using so far won’t be able to be expressed in relational. The aggregations, additional semantics, doesn’t map cleanly, the more object-oriented it becomes the more problematic it will be for relational expression. It’s something we need to consider.
-Would IDEF-1x be better?
-This is something we should keep on the radar and perhaps bring to a different group for consideration.


Continue grouping mechanisms discussion



UI Expand
titleTC Meeting of 20140612 regarding Modeling Issues

DDI TC Meeting
In Attendance: Wendy Thomas (organizer), Johan Fihn, Dan Gillman, Jay Greenfield, Jeremy Iverson, Jon Johnson, Dan Smith 
Secretary: Elise Dunham 

TC used this meeting time to advance work commitments to the DDI 4 Moving Forward Project 
Name, Label, Description
Containment and Reference/What do we reference?* 
*TC decided to begin referring to the Containment and Reference portion of their work as "What do we reference?" at the 2014-06-12 meeting. 

Dan Gillman: Write up a document about his ideas on approaching the name, label, description issue in a rigorous manner 
All: Review and send in feedback on GSIM 1.1 to DDI 3.2 mapping document 

Name, Label, Description
Frame of discussion/background: in previous versions of DDI, we've used ISO/IEC 11179-5 as the basis for our approach. This included a set of 3 objects: Name, Label, and Description. For Name we used a NameType, with each object having a specific name of type="NameType" (i.e. VariableName, ConceptName, etc.) We've made the decision to just use Name as a direct property of the object. Questions are:

  1. What objects should we be using this with?
  2. Is the full triple always required?

Dan Gillman would like to see us put more structure around names, concepts, labels, and designations. He will write up a document where he'll

 lay out his ideas on this issue to give a sense of what the distinctions are and how to structure them. Aiming for early next week; send any questions to Dan in the meantime. The group consents to this plan and will use this document when making its proposal to the modeler group. 
Dan Smith wrote up a document on this issue and discussed each section of it with the group. Highlights from this discussion:

  • Group agrees on requirements Dan outlined in this document
  • Character restrictions: in 4 we will lift character restrictions to allow for support of localized identification schemas. The historical reason for character restrictions is now managed by the ability to capture a DDI lifecycle URN in 2.5: identifiers in 4 will still be able to be represented in Codebook.
  • When we get back to working on administrative metadata we need to pay attention to potential overloading.
  • XML serialization and RDF serialization: Dan has outlined 2 potential strategies for doing this, and says it could be done with either approach or a combination of them. The group responsible for determining the approach are the groups doing the transformations.
  • Dan's document is ready to be presented; it's meant to describe the how's, not the what's—that's for the modelers; the how and the application are intentionally being treated as two separate functions in this workflow.

Containment and Reference/What do we reference?

  • Will discuss fully in another meeting.
  • Changed what we refer to this discussion as to "What do we reference?"

Other TC Business
Dan Smith put out a call on the DDI-user list that starts the mapping of the GSIM 1.1 to DDI 3.2. He asks that everyone look that over and send in any comments. If there's feedback, Wendy will put on the agenda for next week's TC meeting. 
Plans for Next Week
Back to TC 3.2 work: Sampling, weighting and questionnaire development.