Common Use Cases for Preservation Metadata

1. Common Use Cases for Preservation Metadata Deborah Woodyard-Robinson Digital Preservation Consultant deb@woodyard-robinson.com Long-term Repositories: Taking the Shock out of the Future, APSR, NLA, Canberra, Australia ,31 August 2006

2. Use of use cases • Broad use cases : viewed from 2 angles • Metadata must support the functions in a system and the function (aim) of a system A system (Repository) as a use case Functions as use cases

3. PREMIS definitions • Preservation Metadata: Information a Preservation Repository uses to support the digital preservation process. • Digital Preservation Process:functions to maintain viability, renderability, understandability, authenticity & identityof digital material in a preservation context

4. Digital information • Step back further to understand the source of these functions • Digital information exists on 3 levels

5. Intellectual (e.g. it’s a photo of Deb dancing) Conceptual (e.g. it’s a file called IMGP0132.jpg) 0101010111 1001010010 0010011001 Physical (e.g. it’s a CD-ROM)

6. The OAIS recognises these levels and discusses functions to do this as well as the information required to support these functions, i.e. the metadata.

7. OAIS metadata • Packaging Information(i.e. how and where the bits are stored) • Content Information including Representation Information (i.e. how to locate the bits and interpret the bits into data) • Preservation Description Information including • Reference Information • Context Information • Provenance Information • Fixity Information (i.e. how to identify the data and interpret the data into information)

8. Intellectual Preservation Description Information Conceptual Content Information includingRepresentation Information 0101010111 1001010010 0010011001 Physical Packaging Information

9. Understandability Authenticity Identity Intellectual Preservation Description Information Conceptual Content Information includingRepresentation Information Renderability Physical Packaging Information Viability

10. Maintain Renderability Monitor technology Customer Staff Design preservation actions Supply renderable version Repository System Perform preservation actions

11. Use Case: Monitor technology • Description: • Repository staff request or schedule a technology report. • The system creates a report on the file formats, inhibitor types and technology required by repository contents. • An external survey is conducted by the system based on report results and level of preservation required. • The system registers endangered formats and technologies. • The System surveys possible solutions available from available registries. • The system creates a report of findings for repository staff

12. Maintain Renderability Monitor technology Customer Staff Design preservation actions Supporting metadata required for these functions: Object Identifier Preservation level Format Inhibitors Environment Relationships- structural Supply renderable version Repository System Perform preservation actions

13. Maintain Viability Monitor storage media Staff Refresh media Replicate on backup media Content Location Storage Medium Repository System Replace media

14. Maintain Understandablility Record history & provenance Customer Staff Maintain Context Creation details Original file name Relationships – context Rights Events Agents Repository System Understandan object

15. Maintain Authenticity Check Fixity Customer Apply fixity check Read signature Fixity / check-sum details Digital signature details Repository System Apply signature

16. Maintain Identity Apply unique identifier Customer Repository System Resolve unique identifier Object Identifier

17. Application in a system • Different repositories have different needs and will use different functions and therefore different metadata • “Mandatory” if applicable • Possible differences: • Handling objects at rep/file/bitstream level • User community > Understandability details • Authenticity

18. Application scenarios/2 use cases • Government record archives • large volumes of government records to be archived, often under legislative obligation from electronic government initiatives • mandated to preserve records, but also implementing specific retention schedules • more influence over what the producers of records deposit • authenticity is usually a vital aspect

19. Application scenarios/2 use cases • Private sector library (e.g. Wellcome Trust) • very specific collection remit • main users of the collection are internal to the organisation, therefore well defined user group and knowledge base • interest in content only, can easily discard ‘look and feel’ if not desired • can normalise files to one format to manage if desired

20. Government record archives Private sector library Requires: Content Location Storage Medium Viability

21. Government record archives Private sector library Requires: Object Identifier Format details Inhibitors Environment details Relationships- structural Renderability

22. Government record archives Private sector library Requires: Creation details Original file name Relationships – context Rights Events Agents Understandability

23. Government record archives Private sector library Requires: Creation details Original file name Relationships – context Rights Events Agents Understandability

24. Government record archives Private sector library Requires: Fixity / check-sum details Digital signature details Authenticity

25. Government record archives Private sector library Requires: Fixity /check-sum details Digital signature details Authenticity

26. Implementation • PREMIS does not differentiate between what is required to be implicit or explicit • Mandatory means “need to know” rather than “must exist as a metadata element” • Record only if applicable. E.g. signature information required only if signatures are used

27. Example: The National Archives, UK • Identifier types are the same throughout the system so not explicit in metadata • Storage media and location handled by system • Relationships between representation, file and bitstream equivalents are implicit via the structure of data in the system. • Format, inhibitor and environment information is/will be kept via PRONOM Unique Identifiers and the PRONOM registry • i.e. format name, environment details etc are known and explicitly recorded but not held with the object • Levels of preservation are recorded in policies and retention schedules

28. Summary • Problem > solution > functions • Functions > use cases • Use cases > metadata (Reality check 1) • However, do remember:The information you need to know may not need to be explicitly recorded in object metadata to be functional (Reality check 2)