OCLC Online Computer Library Center

The ‘Hows’ and ‘Whys’ of Preserving Digital

MaterialsBrian Lavoie

Research Scientist

OCLC

CARL program: “Here Today, Gone Tomorrow”

June 2, 2004

RoadmapRoadmap

Digital preservation

Why is it important?

How do we do it?

Current initiatives

Rising digital tideRising digital tide

Equivalent of 5 exabytes of new information created in 2002; 92 percent stored on magnetic or optical media

Rush to digitize:– Cultural artifacts (images, audio, video, text)– Electronic publishing (books, journals, newspapers,

databases)– Scholarly and “non-scholarly” communication

(listservs, e-prints, blogs, Web sites, chat rooms)

Growing proportion of scholarly and cultural record manifested in digital form

Opportunities and challengesOpportunities and challenges

Digital technologies offer new opportunities to create, share, re-purpose, and link information …

… but introduce new challenges in managing information

Critical element in managing digital materials is securing their long-term persistence …

… but digital materials have relatively brief “shelf-life”

Bit rot, obsolescence, and otherdigital diseases …

Bit rot, obsolescence, and otherdigital diseases …

Fragile digital storage media:– Computer hard drives, floppy disks, tapes, CD-ROMs,

DVDs, etc.– Subject to rapid media degradation and “bit rot”– Prone to damage from careless handling

Technological obsolescence:– Technological environment between content and user– Technology rapidly changing and evolving– Obsolete technology impairs access to dependent

digital materials

Digital preservationDigital preservation

Preserving digital materials means ensuring they endure into the future

But also: Ensuring they endure in a form compatible with contemporary technology

“Traditional preservation” (books, art, buildings)– Preserve object

Digital preservation– Preserve object AND the means to access and use it

Challenges: technical, legal, economic

Technical challengesTechnical challenges

How do we preserve digital materials?

Menu of digital preservation techniques:– Media refreshment– Migration– Emulation

Digital preservation in action: Camileon Project– Univ. of Michigan and Univ. of Leeds– Practical implementation of emulation– Rescue of British Domesday materials– http://www.si.umich.edu/CAMILEON/

Other technical issuesOther technical issues

Blueprint for a digital archiving system:– Open Archival Information System (OAIS) reference model– Articulates functional components of complete digital

archiving system– Many current digital archives based on OAIS– http://ssdoo.gsfc.nasa.gov/nost/wwwclassic/documents/pdf/

CCSDS-650.0-B-1.pdf

Preservation metadata:– Information “bundled” with archived digital materials;

supports digital preservation process– PREMIS (Preservation Metadata: Implementation Strategies)– http://www.oclc.org/research/projects/pmwg/

Legal challengesLegal challenges

Digital preservation and the right to preserve

Issues:– Digital preservation often occurs while materials still

under copyright– Many digital materials outside custody of institutions

with mandate to preserve

Preserving digital materials under copyright:– Preservation may require reproducing materials– Migration may alter appearance, functionality, etc.

Legal challenges (continued)Legal challenges (continued)

“Custody” and the right to preserve:– Digital materials obtained through license, subscription– Web sites

NESLI (National E-Journals Initiative)– Coordinates e-journal licensing for UK higher education– Model License: requires publishers to preserve content– http://www.nesli2.ac.uk/

Internet Archive– Harvest and stores Web sites for future access– “Cease and desist” policy– http://www.archive.org/

Economic challengesEconomic challenges

Economic sustainability: ability to marshal, on an ongoing basis, sufficient resources to meet preservation objectives

Obstacles:– Preservation typically under-funded– Reliance on one-off, short-term funding sources

Economic infrastructure for digital preservation:– Appropriate allocation of preservation responsibilities– Sufficient incentives to carry out these responsibilities– Efficient organization of scarce preservation resources

Economic infrastructure …Economic infrastructure …Responsibilities:– Recognize “diffused” preservation responsibilities, including

publishers, Webmasters, software developers, etc.

Incentives:– Address potential gaps between preservation objectives and

incentives

Organization:– Leverage infrastructure, exploit economies of scale, eliminate

redundancies

More information:– http://www.oclc.org/research/projects/digipres/incentives-dp.pdf– http://www.clir.org/pubs/reports/pub126/pub126.pdf

Towards a secure digital future …Towards a secure digital future …

Digital technologies facilitate creating and sharing information

Long-term future of digital information threatened:– Fragile digital storage media– Technological obsolescence– Must take steps to preserve digital materials

Challenges:– Effective preservation strategies– Sorting out right to preserve– Allocating resources to digital preservation, and using them

effectively

More information …More information …

PADI (Preserving Access to Digital Information):

http://www.nla.gov.au/padi/

Digital Preservation Coalition:

http://www.dpconline.org/graphics/index.html

Canadian Initiative on Digital Libraries:

http://www.collectionscanada.ca/cidl/pres-preserv-e.html

lavoie@oclc.org