CG Core v2 schema from the DSpace perspective
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The document discusses the development and implementation of the 'cg core' schema within the context of DSpace and Dublin Core metadata standards. It highlights the evolution of the schema, its relationship to DCTerms, and the progress made since its initiation in 2015. The document also addresses technical limitations and the ongoing review and feedback processes in the development of 'cg core' v2, which aims to facilitate meaningful metadata interchange among CGIAR centers.
CG Core v2 schema from the DSpace perspective
- 1. CG Core v2 Schema from the DSpace Perspective Alan Orth CGSpace Technical Manager Monitoring, Evaluation and Learning (MEL) Developers’ Retreat Nairobi, Kenya 3- 6 December 2019
- 2. Dublin Core Schema Context & Landscape DC → QDC → DCTERMS • 1995: DC originates at OCLC workshop in Dublin, Ohio • aka “simple”, consists of fifteen core metadata elements called the Dublin Core Metadata Element Set (DCMES) • 2000: Ongoing process by working groups to develop qualifiers and encoding schemes for the DCMES • 2008: DCTERMS supersedes DC and QDC • Includes and refines previous schemas, adds new fields • Each term has a unique URI, all defined as RDF properties Excellent resource: https://en.wikipedia.org/wiki/Dublin_Core
- 3. Dublin Core in DSpace • DSpace implements Qualified Dublin Core • DSpace partially implements DCTERMS • Simple Dublin Core, Qualified Dublin Core, and DCTERMS are all available for describing items in a DSpace repository • Advanced: DSpace can use “crosswalks” to express metadata in other formats (depending on how good you are with XSLT)
- 4. Value Proposition for a “CG Core” Schema? • Is it bad to say “I don’t know”? • Why not use qualifiers, as permitted by Dublin Core? • dc.subject.ilri • dc.coverage.country • dc.identifier.doi • dc.creator.affiliation • dc.date.embargo • etc... • See DMCI Grammatical Principles section 2.3
- 5. DCMI “Dumb-down Principle” “The qualification of Dublin Core Elements is guided by a rule known colloquially as the Dumb-Down Principle. According to this rule, a client should be able to ignore any qualifier and use the value as if it were unqualified. While this may result in some loss of specificity, the remaining term value (minus the qualifier) must continue to be generally correct and useful for discovery. Qualification is therefore supposed only to refine, not extend the semantic scope of an Element.” “DCMI: DCMI Grammatical Principles”. www.dublincore.org. Retrieved 4 December 2019.
- 6. Value Proposition for a “CG Core” Schema • Similar to the DC → QDC → DCTERMS evolution • Introduction of formal schema with RDF data model • See: agriculturalsemantics.github.io/cg-core/cgcore.rdf • Standardized guidance about metadata fields and controlled vocabularies • For example, using ORCID for unique author identifiers • For example, using ISO 639 alpha 3 for language codes • See: agriculturalsemantics.github.io/cg-core/cgcore.html • Enable programmatic validation of data sets using the schema
- 7. The “CG Core” Dream A “core” schema for meaningful metadata interchange between CGIAR centers, CRPs, etc. • Rise of web-based institutional repositories like DSpace, CKAN, and DataVerse in CG after late 2000s • Harvesting of repositories as means of syndication (no duplication of content!) • Increased interest in reporting and impact assessment • Bonus: build cool things like AReS Explorer and GARDIAN to see all research across the CG in one place!
- 8. Build Cool Things “AReS Explorer”. https://cgspace.cgiar.org/explorer. Retrieved 4 December 2019.
- 9. Progress on “CG Core” Schema • “CG Core” initiative undertaken in 2015 • Formation of Metadata Working Group • CGcore Draft version beta 1 (November, 2016) • Beta version 1.0 (March, 2017) • CG Core v2 “soft ratification” at the Big Data Platform meeting in Kenya (October, 2018) • CG Core v2 review by ILRI, ICARDA, IITA, and WorldFish in Jordan (January, 2019) • CG Core v2 ongoing review by Alan, Abenet, and Marie-Angelique (mid-to-late 2019)
- 10. CG Core v2 Metadata Changes in Practice • Much of CG Core v2 is simply aligning with DCTERMS • For example, in the CGSpace context, some fields gain a more appropriate home within DCTERMS: • cg.identifier.status→dcterms.accessRights • dc.rights→dcterms.license • cg.link.reference→dcterms.relation • dc.description.abstract→dcterms.abstract • Others merely change places: • dc.type→dcterms.type • dc.format.extent→dcterms.extent • dc.relation.ispartofseries→dcterms.isPartOf See the full list: https://alanorth.github.io/cgspace-notes/cgspace-cgcorev2-migration
- 11. Technical Limitations to Adoption in DSpace • DSpace 5.x and 6.x have many hard-coded references to DC fields (see: IncludePageMeta.java) • Impossible to migrate away from some fields: • dc.title • dc.identifier.uri • dc.contributor.author • dc.date.accessioned • etc… • DSpace uses a flat schema, so this is not possible: <dc.creator affiliation="ILRI">Alan Orth</dc.creator>
- 12. Progress of CG Core v2 Implementation • CGSpace public test server is running CG Core v2 as of November, 2019 • Item submission ✓ • Item display ✓ • OAI-PMH ✓ • REST API ✓ • CGSpace-specific DSpace 5.x code modifications are available on GitHub • Thorough implementation notes also available • Soon solicit feedback from CGSpace community • Massive effort for downstream consumers of CGSpace • How long should the notice period be?
- 13. Acknowledgements Medha Devare, Carlos Quiros, and Martin Mueller for getting the first few drafts and betas of CG Core out the door. Marie-Angélique Laporte for being receptive to feedback and for bringing “CG Core v2” into open, accessible development on GitHub.
- 14. This presentation is licensed for use under the Creative Commons Attribution 4.0 International Licence. better lives through livestock ilri.org ILRI thanks all donors and organizations which globally support its work through their contributions to the CGIAR Trust Fund
Editor's Notes
- #2: Disclaimer: I am not a metadata expert or ontologist!
- #3: Background context and evolution of Dublin Core, to say nothing of other schemas.
- #5: Why didn’t we just make use of qualifiers, as permitted by Dublin Core?
- #6: Why didn’t we just stick to dc.subject.ilri, dc.identifier.doi, dc.coverage.country, etc as permitted by Dublin Core?
- #7: Medha Devare, Carlos Quiros, Martin Mueller, Marie-Angelique.
- #8: Medha Devare, Carlos Quiros, Martin Mueller, Marie-Angelique.
- #9: Medha Devare, Carlos Quiros, Martin Mueller, Marie-Angelique.
- #10: Medha Devare, Carlos Quiros, Martin Mueller, Marie-Angelique.
- #11: Others are more complicated. Need to see reference schema to understand.
- #13: As far as I know CGSpace is the only party working to implement CG Core v2 currently.