1. Digital Libraries, R. Jantz - Feb. 26, 2002
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Digital Preservation - Outline
Introduction - Definitions, Facts, Challenges
Digital Archiving – A Life Cycle View
– Metadata
– Strategies
– RUL Projects
Trusted Digital Repositories
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Digital Dark Ages?
As we move into the electronic era of digital objects it is important to know
that there are new barbarians at the gate and that we are moving into an
era where much of what we know today, much of what is coded and
written electronically, will be lost forever. We are, to my mind, living in the
midst of digital Dark Ages; consequently, much as monks of times past, it
falls to librarians and archivists to hold to the tradition which reveres
history and the published heritage of our times. (Kuny, 1998)
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Preservation
“The urge to preserve is endemic to our roles as librarians.”
“The patent office, home to nearly 6.5 million patents dating to
1790, is converting to an electronic database and discarding a
significant portion of its paper files after they have been scanned
and digitized.” -Mitchell, A. (2001). Ingenuity’s Blueprints, Into History’s Dustbin. NY
Times. December 30, 2001, p. A1.
A scenario: A truck loaded with hazardous waste is headed toward
a dump site. Will our descendants know where we have buried
the waste? (Bide, et al, 1999)
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Digital Preservation – Some Numbers
$20 Trillion loss of information expected over the next 20 years
(Lysakowski and Leibowitz, 2000)
– Within 10 years, the total number of electronic records could be doubling
every 60 minutes.
– From an economic model, the cost of converting from MS-Office95 to
Office97 is estimated at 711,110 work years.
80 Million books in the US are rapidly deteriorating
Yale University states that 80% of their collection is endangered.
Print material
All print material (ascii text) published in the world each year could be
stored in about 5 terabytes
Images
Over 80 billion photographs are taken each year which would take 400
petabytes to store.
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Numbers – continued
(from: http://www.ccsf.caltech.edu/~roy/dataquan/)
Megabyte – one million bytes
Gigabyte – 1000 megabytes
Terabyte – 1000 gigabytes
10 terabytes: the printed collection of the US Library of
Congress
Petabyte – 1000 terabytes
2 petabytes: all the material in US academic research libraries
Exabyte – 1000 petabytes
5 exabytes: all words ever spoken by human beings
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Preservation in Digital Libraries
Preservation:“The managerial, financial, and technical issues involved in
preserving library (or archive) materials in all formats - and/or their
information content - so as to maximize their useful life” (Eden, 1997)
Digital preservation is defined as the managed activities
necessary for ensuring:
1. The long term maintenance of a byte stream and
2. Continued accessibility of the contents thru time and changing technology.
Digital Libraries vs. Digital Archives: Archives make a commitment to
long-term preservation of digital information. (Joint Task Force on Digital
Archiving)
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Why Would You Digitally Preserve?
Protect original print artifact
Provide access by accurately representing originals
Preserve material that exists in electronic form only
Enhance research by “improving” originals
– High resolution imagery to study details
– Searchable text
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The Challenges of Digital Preservation
Lack of standards (or too many standards)
Lack of documentation on production and use
Cost and rapid obsolescence of technology
Impermanence of the medium
Mutability of the content (easily changed – legal
issues)
Version control
Need to guarantee integrity of digital information
Migration of information (driven by external factors)
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What to Archive – A Checklist
Historical and research value
Aesthetic and artistic merit
Uniqueness of an item
Subject content – relevant to Institution
Access – Restrictions and inventory
Condition
Frequency of use – frequency of change
Ownership
Redundancy – concern for loss or modification
Length of preservation
Is any other institution archiving the material?
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Candidates for Preservation
Material created (not digitized) in digital format
– Reference databases (online catalogs, subject specific indexes, etc)
– Electronic journals
– Digital maps
– Data
– Websites (e.g. research guides, web-based databases, documents)
Government information
– Census data, international statistics (Do we rely on the government to preserve this
material?)
– Consortiums such as Inter-university Consortium for Political and Social Research
(ICPSR) have a role.
Print material/manuscripts that are digitized for access and/or preservation:
– Original documents not retained (e.g. as in the NJ Environmental Digital Library)
– Original document retained (as in Special Collections)
Electronic (analog) media that is digitized (audio, video tapes)
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Digital Archiving – A Life Cycle View
1. Creation
2. Acquisition and Collection Development
3. Identification and Cataloging
4. Storage
5. Preservation (incl. Metadata)
6. Access
from (Hodge, 2000)
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Digital Preservation Strategies
Migration: transferring digital materials from one media or format to
another because of obsolescence, failure in media, software updates,
standards, etc.
Emulation: refers to the process of mimicking, in software, a piece of
hardware or software so that other processes think the original
equipment/function is still available in its original form.
(http://www.nla.gov.au/padi/topics/17.html)
Encapsulation: A technique of grouping together a digital object and
anything else necessary to provide access to that object. This
technique aims to overcome the problems of the technological
obsolescence of file formats because the details of how to interpret the
digital bits in the object can be part of the encapsulated information.
(http://www.nla.gov.au/padi/topics/17.html)
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Migration of Digital Information
Reasons for Migration:
Medium refreshing (e.g. rewrite a CD)
Medium conversion (diskette to CD)
Format conversion (ascii to pdf)
Version upgrade (Office97 to Office2000)
Migration of technical environment (W98 to NT)
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The Migration Process
Error Prone
Labor intensive and expensive
Governed by external factors
The only approach that works for now
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RUL Projects – A Sampling
Medieval Early Modern Data Bank
Eagleton Public Opinion Polls
The Augustine Collection
REALITI – A Digital Preservation Framework
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Medieval Early Modern Data Bank - MEMDB
Characteristics:
At: http://www.scc.rutgers.edu/memdb
Content: commodity prices in the medieval period
Access: public domain
Compiler: Co-directors of MEMDB
Owner: RUL?
Archiver: (who should archive?)
Type: Database on the web
Format: html, Active server pages, MS-Access, html
Metadata req’mts: numeric data
Questions: What is the primary document? How long should it be preserved?
Extent of “document”? Owner? Preserve look & feel?
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Eagleton Public Opinion Polls
Characteristics
• At: http://www.scc.rutgers.edu/eagleton_tst
• Content: New Jersey public opinion (1970 - )
• Access: public domain
• Compiler: Eagleton Institute
• Owner: Eagleton/Star Ledger
• Archiver: RUL/Scholarly Communication Center
• Type: database on the Web
• Format: html, MS-Access, portable spss files
• Metadata req’mnts: Questionnaires & numeric data
• Questions: Preserve “look & feel”, spss (proprietary software)
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The Augustine Collection
Characteristics
• At: http://www.scc.rutgers.edu/augustine
• Content: Photographs from 19th Century New Jersey Shore
• Access: public domain
• Compiler: William F. Augustine
• Owner: RUL Special Collections
• Archiver: RUL Special Collections
• Type: image archive
• Format: html, jpeg
• Metadata req’mnts: original artifacts
• Questions: image format, preserve digital archive, individual items/collection
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REALITI – A Digital Preservation Framework
(Rutgers Electronic Access to Library Information thru Technology Integration)
Characteristics
• At: http://www.scc.rutgers.edu/realiti
• Content: Civil War period in New Jersey
• Access: public domain
• Compiler: RUL Special Collections
• Owner: RUL
• Archiver: RUL Special Collections/SCC
• Type: Images on the Web
• Format: html, ColdFusion, MS-Access, PDF, djvu,tiff
• Metadata: Preservation, multiple formats
• Questions: formats, compression, metadata, original artifact
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Preservation Metatdata for Digital Collections*
Collection Level
1. Persistent identifier:
2. Date of creation:
3. Structural type: (e.g. ascii text, jpeg images, etc)
4. Technical infrastructure: files, databases, html, etc.
5. File description
6. System requirements:
7. Installation requirements:
8. Storage information:
9. Access inhibitors:
10. Access facilitators:
11. Preservation action permission:
12. Validation: (information about validation
mechanism)
13. Relationships (to other objects):
* (from National Library of Australia: http://www.nla.gov.au/preserve/pmeta.html )
(continued)
14. Quirks: (any characteristic that may cause loss in
funtionality)
15. Archiving decision (work):
16. Decision reason (work):
17. Institution responsible for archiving decision:
18. Archiving decision (manifestation):
19. Decision reason (manifestation):
20. Institution Responsible for Archiving Decision
(manifestation)
21. Intention Type
22. Institution with preservation responsibility
23. Process
24. Record Creator
25. Other
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Trusted Digital Repositories
(http://www.rlg.org/pr/pr2001-attributes.html)
A Proposed Framework for a Trusted Archival Agent:
Administrative – adherence to agreed upon standards
Organizational – commitment to management on behalf of depositors
Financial – adherence to good business practices
Technological – infrastructure in place with upgrade policies
Security – policies for security, auditability, and backup
Procedural – Repository practices will be in place and documented.
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Possible Organizational Models
(Who might be a digital repository)
Originators (e.g. individual researchers)
Publishers (What happens when the publisher goes out of business?)
Libraries, museums, and other conservator institutions
National libraries and archives
Cooperative service agencies (e.g. OCLC, RLG, ICPSR for social science
research)
Segmented market providers (e.g. Bell & Howell for preserving
dissertation literature and Early English Books)
Private storage providers
Computer centers
Scholarly associations (e.g. American Institute of Physics)
Indexing and abstracting services
Certified digital archives.
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Institutional Efforts
OCLC and Web Document Digital Archive (WDDA) Project
– Tools for libraries and archives to preserve and maintain access to digital content
– At: http://www.oclc.org/digitalpreservation
RLG Cultural Materials
– Cultural Materials is being developed through members to set the conditions for
contributing and distributing their digital surrogates of valuable collections.
– The goal is a growing, significant, online resource and service solution.
– At: http://www.rlg.org/culturalres
LOCKSS – A permanent web publishing and access system
– Addresses problem of material no longer available from the publisher
– Modeled on distributed print libraries. Reich, et al, (2001). D-Lib Magazine, 7, (6).
OAIS – Open Archival Information System Reference Model
– Requirements for any system responsible for preserving any type of information over a
long period.
– At: http://ssdoo.gsfc.nasa.gov/nost/isoas
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Digital Preservation – Concluding Thoughts
Librarians and archivists are a key to the solution.
“A major academic scandal will have to happen first . .
.” in order to focus attention and resources. (Graham,
2000).
A combination of solutions will be employed including
migration and emulation.
Digital “archaeology” will be used to recover lost data.
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Preservation Resources on the Web
Institutional Issues:
– ARL Preservation Program (http://www.arl.org/preserv/index.html)
Digital Preservation Needs and Requirements in RLG Member Institutions
(http://www.rlg.org/preserv/digpres.html)
– RLG DigiNews (http://www.rlg.org/preserv/diginews/)
Technical Information/Papers:
– Avoiding Technological Quicksand
(http://www.clir.org/pubs/reports/rothenberg/contents.html)
– PADI - Preserving Access to Digital Information - from the National Library of
Australia (http://www.nla.gov.au/padi/).
– Background Papers and Technical Information - from LOC American Memories site
(http://memory.loc.gov/ammem/ftpfiles.html)
– Preservation of electronic information - a bibliography
(http://homes.ukoln.ac.uk/~lismd/preservation.html)
– Digital Imaging Tutorial - http://www.library.cornell.edu/preservation/tutorial/
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More Information on the Web
Technical Information/Papers (continued):
– CLIR Publications (http://www.clir.org/pubs/reports/reports.html)
– Kuny, T. (1998/May). The digital dark dges? Challenges in the preservation of electronic
information. International Preservation News, (17), At http://www.ifla.org/VI/4/news/17-
98.htm#2
– Hodge, G. M. (2000). Best practices for digital archiving: An information life cycle
approach. D-Lib Magazine, 6, (1), available at:
http://www.dlib.org/dlib/janauary00/01hodge.html
Handbooks:
– Hunter, G. S. (2000). Preserving Digital Information: A How-To-Do-It Manual, New York:
Neil-Schuman Publishers
– Sitts, M. K. (2000). Handbook for Digital Projects: A Management Tool for Preservation
and Access, Andover, Massachusetts: Northeast Document Conservation Center
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References
Bide, M, Potter, E, &Watkinson, A. (1999) , Digital Preservation: an introduction to the standards issues
surrounding the deposit of non-print publications. At: www.bic.org.uk/digpres.doc
Graham, P. (2000). RLG and Archiving at the heart of the research library mission. RLG News. Winter 2000.
(50). P. 12 – 13.
Graham, P. (1998/February). Digital strategies for the Rutgers University Libraries: a white paper draft.
DRAFT 4.
Hedstrom, M. & Montgomery, S. (1998). Digital Preservation Needs and Requirements in RLG Member
Institutions: A Study Commissioned by the Research Libraries Group. Available at:
http://www.rlg.org/preserv/digpres.html
Hodge, G. (2000). Best practices for digital archiving: An information life cycle approach. D-Lib Magazine, 6,
(1). Available at: http://www.dlib.org/dlib/january00/01hodge.html.
Lysakowski, R. & Leibowitz, Z. (2000). Looming information age crisis expected to cause trillion-dollar losses
over the next 20 years: Titantic 2020 – a call to action. Available at: http://www.censa.org.
Rothenberg, J. (1998/January). Avoiding Technological Quicksand: Finding a Viable Technical
Foundation for Digital Preservation. Available at: http://www.clir.org/pubs/reports/rothenberg/contents.html
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Migration & Complexity of the Technical
Environment
PCs, disks, CDs Server, storage, Network
Hardware
Operating System W95/98/2000 Unix/NT
Network TCP/IP TCP/IP
Application Software
Adobe, Netscape
Word, SPSS
Servers: web, file,
email, etc
Formats (extensions)
Pdf, doc, wpd, txt, gif, jpeg,
tiff, eoo, por, ebx, mdb
Client Server
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Preservation in Digital Libraries
Preservation:“The managerial, financial, and technical issues involved in
preserving library (or archive) materials in all formats - and/or their
information content - so as to maximize their useful life” (Eden, 1997)
Digital preservation: The term refers exclusively to the preservation
(whatever exactly that entails) of material which is available [solely?] in
electronic form (Bide, 1999).
And the digital version is considered to be the primary archival item.
(Hedstrom, 1998)
Digital Libraries vs. Digital Archives: Archives make a commitment to
long-term preservation of digital information. (Joint Task Force on Digital
Archiving)
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Digital Archiving- Getting Started
Form an archiving working group
Prepare a preliminary policy statement
Trial the policy statement with several small, existing projects
Examine what others are doing and bring in best ideas.
Collaborate with others who are interested in digital in
preservation.
Initiate forums on digital archiving; invite colleagues, students,
researchers, etc.
Submit a recommendation for a digital archiving program and
next steps.
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Trusted Digital Repositories
(http://www.rlg.org/pr/pr2001-attributes.html)
A Proposed Definition (from RLG document):
Technology Infrastructure
– Auditability, security, and communication
– Backup policies incl. avoiding, detecting and restoring corrupted data
Organization
– Certification
– Compliance
– Reputation and performance
– Agreements between creators and providers
– Open sharing of what is being preserved and for whom
– Balanced risk, benefit, and cost