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DCMI Type Working Group

Dublin Core Metadata Initiative - Type Working Group

DC2002 Type Working Group Meeting, 2002-10-17 (9:00-10:30)

Chair: Ann Apps <>

Main Points

  • Moving and Still Image Proposal. It was decided to go ahead to develop this. The work will be led by Simon Pockley. We have to decide how to solve the 'Image problem', and determine any environmental impact.
  • We will shelve any other suggestions for new types for now - we can work on only one proposal at once.
  • We will continue accumulating the list of standard and commonly used encoding schemes. The standard ones will be registered with DCMI.

Report of DC2002 DC-Type Working Group Meeting

1. Moving Image Proposal. The main purpose in calling the meeting was to discuss the proposal from Simon Pockley, to add a Moving Image type to the DCMI Type Vocabulary. Simon presented his views and the work he has done so far. Simon has sent a more detailed report to the Type WG email list. These are the main points:

  • The proposal has a lot of support, particularly from others in the Moving Image community including MPEG and Vide
  • We would need to propose a Still Image type as well. Currently the definition of the Image type includes both still and moving images. This definition cannot be changed because it would break existing applications. There is concern to maintain high-level interoperability.
  • Stability of DC is important. The current high-level typelist could be used in conjunction with more specific vocabularies. So is a specific Moving Image type necessary?
  • There were several suggestions about how to solve the 'still image' problem:
    • Propose 2 new types, Moving Image and Still Image, and deprecate Image.
    • Propose 2 new types, Moving Image and Still Image, in addition to Image. Require that people have 2 instances of dc:type in their metadata, one of Moving or Still Image, and also Image. This effective coupling of the image types would be included in the definitions of Moving and Still Image. This is know as "Stu's hack". This solution would allow for interoperability with existing applications. It would also allow people to continue using just Image if they do not wish to distinguish the type of image.
    • Have a parallel list to the DCMI Type Vocabulary, eg DCMIType2, which does include Moving and Still Image.
    • Resurrect a second-level DCMI approved list, which could include Moving and Still Image as 'children' of Image in the top-level list. This does not seem a sensible option, given the effort which would be involved and lack of success in the past. It appeared that the second option, "Stu's hack", was the most viable, if not very elegant.
  • There was support from the group at the meeting to go ahead and develop the proposal in the Type Working Group. Simon will lead this work.
  • We need to find information about any environmental impact this would have, and how people are using Image now.
  • If possible we should get support (written letters) from significant bodies.
  • We need evidence that this change will bring additional benefit to the community.
  • We should announce to dc-general that we are working on this

2. Proposals for Further Types. There were suggestions on the WG list before DC2002 that 2 further types should be proposed: multimedia and web page. There was some support for and discussion of 'multimedia' at the meeting. Support for specific aplications like Flash could be provided by using dc:format. If there is no suitable MIME type a request should be made to IMT. It was felt that it would be very difficult to develop a precise definition for multimedia. Also it was agreed that the Type WG should work on only one proposal at one time.

3. Standard Type Encoding Schemes. The WG will continue to add to the list of standard and commonly used encoding schemes for Type. Proposals will be written to request registration by the DCMI Usage Board for some of the standard encoding schemes.

4. Guidance Document. We are still looking for volunteers to write the Guidance Document. Maybe people who have developed their own domain or project typelists could share this experience.