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For those of you attending the DLF Fall Forum next week, there will be a discussion session on Tues. Nov. 6 from 5:00-6:00pm on Establishing Best Practices for use of PREMIS within METS. Below is some background and issues to be addressed during this session. This is also available at: http://www.loc.gov/premis/best-practices-premismets-20070809.doc The first draft of the best practices is at: http://www.loc.gov/premis/dlf-premis-mets-questions.doc ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^ Rebecca S. Guenther ^^ ^^ Senior Networking and Standards Specialist ^^ ^^ Network Development and MARC Standards Office ^^ ^^ 1st and Independence Ave. SE ^^ ^^ Library of Congress ^^ ^^ Washington, DC 20540-4402 ^^ ^^ (202) 707-5092 (voice) (202) 707-0115 (FAX) ^^ ^^ [log in to unmask] ^^ ^^ ^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------------------------------------------------ Questions for DLF Discussion session on: Establishing Best Practices for use of PREMIS within METS Nov. 6, 5:00-6:00 (Walnut Room, 3rd floor) A draft best practices document was distributed to the METS and PIG lists in August 2007. There was some discussion and comments about various points. Moving this work forward is important for institutions implementing PREMIS in a METS context and for the possible exchange of METS documents between repositories. Questions addressed in the draft are below with a brief summary of discussion. 1. Use of PREMIS schemas in METS sections Most agreed with using premis:object in techMD, premis:event in digiProv; premis:rights in rightsMD; premis:agent with appropriate section (digiProv or rights). Some may want to use mdRef instead of mdWrap, referring to metadata from the appropriate section (using xPointer and xLink). 2. Number of sections to use Better to specify than leave it open for specific implementations; repeating subelements under amdSec with use of ID/IDrefs would be appropriate. 3. Use of PREMIS container Most wanted to use the PREMIS container only if keeping all PREMIS metadata together. This may apply to either mdWrap or mdRef. 4. Use of PREMIS with format specific technical metadata schemas Ideally those elements defined in both PREMIS and format specific schemas are only in one place because of inconsistencies that may arise. There was a suggestion to use xPath expressions to minimize redundancies. Another suggestion was to have a premis element with IDref to an mdSecType containing format specific metadata. Note that the PREMIS Editorial Committee is considering a mechanism for extensibility to keep format specific metadata together with PREMIS metadata. When applied to METS that would mean optionally adding format specific (e.g. MIX) metadata in the same section as PREMIS (or if using mdRef in the same XML document). 5. METS structMap and PREMIS structural relationship elements Most respondents suggested using the METS structMap with no redundant PREMIS elements. 6. Other METS redundancies Use PREMIS for attributes that are also defined in METS (e.g. CHECKSUM, SIZE) with no redundancies. There was also a suggestion to have a pointer (a new element or attribute, e.g. .valuePointer.) that could point to another section of the METS document where the attribute is, usually using xPath. 7. METS ID/IDREF and PREMIS identifier elements Some thought using ID/IDRef is already well established in METS and should be used. There was a suggestion to use the XML construct KEY and KEYREF (although this approach did not seem well understood). Issues to be addressed at the discussion session 1. Is it possible to even propose a best practices document without a lot more experimentation? Are there advantages to waiting for some experience? What would people do in the meanwhile? 2. Go over the issues and consider whether there is clarity on which choices might be included in a best practices document (assuming the above results in a desire for such a document). 3. Consider changes that might be needed to METS for PREMIS use. Note that a request is going to the METS Editorial Board to include more specific values for MDTYPE (to reference each of the separate PREMIS schemas). 4. Is it desirable to have the option of using PREMIS for all technical metadata? i.e. an extensibility mechanism to include format specific metadata within a PREMIS expression. 5. Using METS and PREMIS for compound objects when there is more than one representation (in PREMIS terms) in one METS document for the intellectual entity. Is the structMap used.one or more? This was brought up on the METS and PIG lists. http://listserv.loc.gov/cgi-bin/wa?A2=ind0710&L=mets&T=0&X=1A015F316C0D5EE2B8&P=417