Digital Curation and Trusted Repositories: Steps Toward Success

Digital Curation and Trusted Repositories: Steps Toward Success

Christopher A. Lee and Helen R. Tibbo
School of Information and Library Science, University of North Carolina, Chapel Hill, NC
Tel: (919)962-8366 Fax: (919)962-8071
Email: {tibbo, callee AT ils DOT unc DOT edu


This is an introduction to a special issue on digital curation and trusted repositories. The authors summarize some of the main opportunities and challenges of digital curation. They then describe the workshop which generated the papers in the special issue, explore some of the main themes from the workshop and provide background on this special issue.


digital curation, digital preservation, audit, certification, trusted repository

Opportunities and Challenges of Digital Curation

Digital technologies allow us to create, manipulate, store, and make accessible all manner and amounts of information never before possible, yet these same technologies imperil the longevity of the very objects they produce and require very different management than what has been practiced in the paper-based world. A few institutions have been engaged in digital curation activities for several decades, but most institutions are very new to digital curation and do not yet have established practices or resource streams for ensuring success. There are also many fundamental open research questions related to long-term digital preservation. Fortunately, there is a growing awareness of the need to preserve access to digital assets and recognition that digital curation is one of the grand challenges of the early 21st Century (Brophy and Frey 2006; Charter on the Preservation of the Digital Heritage 2003; Fitzgibbon & Reiter 2004; Hedstrom 2003; Hedstrom & Ross 2003; Levy 1998; Library of Congress; NSF Cyberinfrastructure Council 2007; Ross 1998; Rothenberg 1995; The State of Digital Preservation 2002; Tibbo 2003).

A decade of work in digital preservation and access since the Taskforce on Digital Archiving report (Garrett and Waters 1996) to the Commission on Preservation and Access (CPA) and the Research Libraries Group (RLG) has resulted in a set of strategies, technological approaches, and activities now termed “digital curation.” While still an evolving concept, “digital curation” can be defined as “the active management and preservation of digital resources over the life-cycle of scholarly and scientific interest, and over time for current and future generations of users.” (Joint Information Systems Committee 2003). The Joint Information Systems Committee (JISC), the UK funder of the Digital Curation Center (DCC), notes that implicit in data curation specifically, and digital curation more generally, “are the processes of digital archiving and digital preservation,” but that “it also includes all the processes needed for good data creation and management, and the capacity to add value to generate new sources of information and knowledge.” (2003). Digital curation involves the management of digital objects over their entire lifecycle, ranging from pre-creation activities wherein systems are designed, and file formats and other data creation standards are established, through ongoing capture of evolving contextual information for digital assets housed in archival repositories

Digital curation involves selection and appraisal by creators and archivists; evolving provision of intellectual access; redundant storage; data transformations; and, for some materials, a commitment to long-term preservation. Digital curation is stewardship that provides for the reproducibility and re-use of authentic digital data and other digital assets. Development of trustworthy and durable digital repositories; principles of sound metadata creation and capture; use of open standards for file formats and data encoding; and the promotion of information management literacy are all essential to the longevity of digital resources and the success of curation efforts. The foundational vision of the DCC is that “long term stewardship of digital assets is the responsibility of everyone in the digital information value chain” and that “the maintenance, usability and survival of digital resources depends on regular planned interventions; care needs to be taken at conception, at creation, during use, and as use transitions to lower levels” (Rusbridge 2005). Digital curation extends far beyond repository control and involves attention to content creators and future users.

Work on digital preservation and access in the past decade has resulted in many projects and networks (e.g., CAMiLEON; CASPAR; CEDARS; DELOS Preservation Cluster; DigCCurr; DigitalPreservationEurope; Giaretta 2006; InterPARES; PLANETS; LDB; Lee, Tibbo, and Schaefer, 2007; Library of Congress; nestor; Potter 2002; PRESTO; PrestoSpace; Slats and Verdegem 2004; van der Werf-Davelaar 1999); numerous metadata and encoding standards (e.g. Dublin Core; METS, PREMIS); open repository platforms (DSpace; Fedora; LOCKSS; SRB); and a set of common concepts and terminology, elaborated in the Reference Model for an Open Archival Information System (OAIS) (2002) . The later has become the foundation upon which most, if not all, serious digital archives and repositories trusted to preserve and provide access to digital assets for the long-term are being built. A working group of RLG and OCLC has described the attributes and responsibilities of such trusted repositories (2002). In August 2005, a joint Task Force of RLG and the U.S. National Archives and Records Administration (NARA) published "An Audit Checklist for the Certification of Trusted Digital Repositories." While analogous in functions, digital repositories, as evidenced in the certification checklist, require staff with a different set of skills, especially in terms of technical expertise, than did the libraries and archives of the paper-based world. Such a realization led to the workshop that served as the basis for this special issue of JODI.

Workshop on Digital Curation and Trusted Repositories: Seeking Success

The Workshop, Digital Curation and Trusted Repositories: Seeking Success, was held on June 15, 2006 in conjunction with the Joint Conference on Digital Libraries (JCDL 2006, June 11-15, 2006 - Chapel Hill, NC, USA). It was the most highly attended workshop at JCDL 2006, with more than 60 participants. Its main organizers were Helen Tibbo and Christopher (Cal) Lee of the University of North Carolina at Chapel Hill (UNC-CH), with considerable assistance from Carolyn Hank, TRLN Doctoral Fellow, UNC-CH. Members of the Workshop Program Committee were: Philip Eppard, SUNY-Albany; Cal Lee; Karen Markey, Univerisy of Michigan; Soo Young Rieh, University of Michigan; Helen Tibbo; and Elizabeth Yakel, University of Michigan.

Participants in the Workshop were asked to consider the following questions: Will adherence the RLG-NARA Checklist, by itself, ensure a successful digital repository, especially the institutional repositories emerging on university campuses today? What are the most promising approaches for implementing the attributes? What does trust really mean in the context of a contributor-based repository, and will individuals or organizations contribute to a repository just because they trust that it will preserve digital assets over time? What incentives and assistance are needed? What is the role of the archivist vis-a-vis the digital life cycle and the stewardship of digital assets over time? What, indeed, constitutes a successful digital repository and how can we ascertain and measure such success?

The workshop served as a forum for discussion of how the emerging principles of digital curation, "the active management and appraisal of data over the life-cycle of scholarly and scientific interest" ("What is Digital Curation?"), can work with technical and managerial models to produce trustworthy long-term digital repositories. The workshop was planned to serve an audience of professionals engaged in digital curation and digital repository activities, including digital repository developers and curators; digital archivists and electronic records managers; institutional repository developers; institutional administrators and policy developers; digital librarians; scholars engaged in research intended to benefit the above; and researchers and administrators charged with preserving research data. The overall objective of the Workshop was to bring together a group of diverse professionals, representing a range of experience and expertise, to allow detailed exploration on the issues of digital curation, trusted digital repositories, and assessing success.

There as a rich set of discussions at the workshop, including sixteen presentations (listed in the order in which they were presented):

  • "Setting the Stage: Curation Trust, and Evaluation" - Helen Tibbo seeded the discussion, by summarizing the rationale behind certification for advancing trustworthy repositories and the intended role of the workshop.
  • "Overview of the State of Institutional Repositories" - Clifford Lynch, Coalition for Networked Information, provided a broad and informative overview of the state of efforts to develop institutional repositories (IRs)and provided some words of caution and potential next steps
  • "Update on the MIRACLE Project Census on Institutional Repositories " - Karen Markey, University of Michigan (presenting on a paper that she co-authored with Elizabeth Yakel, Beth St. Jean, Jihyun Kim, Soo Young Rieh, and Yong-Mi Kim) provided preliminary findings from the first phase of he MIRACLE (Making Institutional Repositories A Collaborative Learning Environment) Project, which investigated IR activities "in American colleges and universities to identify models and best practices in the administration, technical infrastructure, and access to repository collections." Markey reported on survey responses related to the types of investigative activities before deciding to implement an IR, perceived benefits, staffing, methods of recruiting content, costs, and reported next steps toward implementing an IR.
  • "What Constitutes Success in a Digital Repository?" - Kenneth Thibodeau, U.S. National Archives and Records Administration, contended that evaluation of repositories should be informed by "empirical data on the purpose of each repository and the institutional, cultural and resource context in which it operates." This should include "how a repository balances the competing objectives of preservation and dissemination, whether it is defined primarily in terms of a community of producers or a community or users, and the extent to which it operates in isolation or in collaboration with other institutions."
  • "Faculty Contributions to IRs " - Jihyun Kim, University of Michigan, reported on a study of factors that motivate or impede faculty contributions to IRs. Kim presented a conceptual model of relevant factors and then summarized findings from a survey of faculty whose materials were deposited in the IR of a major research university.
  • "Metadata Use in OAI-Compliant Institutional Repositories" - Miles Efron, Appalachian State University, discussed the use and quality of Dublin Core metadata in IRs that participate in the Open Archives Initiative. He argued that IR developers should create well-structured metadata to better support information retrieval.
  • "The Information Network Overlay: An Architecture for Contextual Metadata Needed for the Curation Process and Repositories that Support Digital Scholarship" - David Gewirtz, Yale University, argued that capture of contextual metadata related to a digital object at the "consume phase of its life cycle" is necessary for integrity, re-use, trust. Gewirtz raised three fundamental questions: " (1) What does contextual metadata look like? (2) How is contextual metadata created? and (3) How can repository users take advantage of contextual metadata?"
  • "Services Make the Repository" - Alison Jones and Anne Sauer, Tufts University (presenting on a paper authored by Robert Chavez, Gregory Crane, Anne Sauer and Alison Jones, Adrian Packel, and Gabriel Weaver), reported on a collaborative effort to move collections from the Perseus Project into a Fedora-based repository at the Tufts University Digital Collection and Archives. Jones and Sauer elaborated a number of services that could allow repositories to accommodate both current and unforeseen future needs of stakeholders.
  • "Building Relationships: A Foundation for Digital Archives" - Jonathan Crabtree, Odum Institute, and Darrell Donakowski, Interuniversity Consortium for Political and Social Research, discussed the Data Preservation Alliance for the Social Sciences (Data-PASS) Project, which is a partnership between six major repositories of social science data, funded by the National Digital Information Infrastructure and Preservation Program (NDIIPP). Crabtree and Donakowski identified several potential benefits of such collaborations: communication and knowledge sharing; improved relationships with data providers; building networks of relationships with software developers; and adoption of common standards.
  • "The Archive Ingest and Handling Test: Implications of Diverse Content and Diverse Repository Practices" - William LeFurgy, Library of Congress (presenting on a paper he co-authored with Martha Anderson) described the Archive Ingest and Handling Test, which was a year-long project involving the transfer, ingest, and export of a test data set among LC and four partner universities, as part of NDIIPP. LeFurgy discussed the value and costs associated with heterogeneous approaches to digital curation.
  • "The RLG/NARA Audit Checklist for Certifying Digital Repositories" - Rolin Dale, then at the Research Libraries Group, discussed the history and rationale behind recent efforts related to certification and audit of digital repositories. She also provided insights on future directions.
  • "Government Archives and Certification" - Bruce Ambacher, who was then at the U.S. National Archives and Records Administration, provided a government archives perspective on the RLG-NARA Checklist. Ambacher discussed issues unique to government archives and issues shared with other types of repositories; and he emphasized "the broader value to be gained from their participation in a successful audit checklist process."
  • "The nestor Catalogue of Criteria for Trusted Digital Repository Evaluation and Certification" - Stefan Strathmann, Göttingen State and University Library (presenting on a paper that he co-authored with Susanne Dobratz, Humboldt-University Berlin, and Astrid Schoger, Bavarian State Library) described the general approach behind the German nestor (Network of Expertise in Long-Term Storage of Digital Resources) project for self-assessment of trusted long-term digital repositories, as well as its relationships with formal certification processes.
  • "Assessment of RLG Trusted Digital Repository Requirements" - Reagan W. Moore, San Diego Supercomputer Center, and MacKenzie Smith, Massachusetts Institute of Technology, explained how they used DSpace and the Storage Resource Broker (SRB) in the mapping of management policies from the RLG-NARA Checklist into formal rules. They discussed the types of rules, state information required, the desired level of granularity for applying the policies, and the potential of the Intelligent Rule Oriented Data Systems (iRODS) to support the development and management of trustworthy digital repositories.
  • "The Role of Evidence in Establishing Trust in Repositories" - Andrew McHugh, Digital Curation Centre (presenting on a paper he co-authored with Seamus Ross, Digital Curation Centre), described the efforts of the Digital Curation Centre to provide audit and certification services for digital repositories in the United Kingdom. Experience in carrying out pilot audits suggests a need for more detailed exploration of how the satisfaction of requirements in the RLG-NARA Checklist (as well as the nestor Catalogue) can be demonstrated and measured. McHugh discussed the role of evidence in certification and elaborated several types of evidence that could support audit processes.
  • "Recap and Review: It's A Checklist, Not a Do List " - Christopher (Cal) Lee (see below)

Major Workshop Themes

This section is based on the "selective synthesis" of major themes that Cal Lee provided at the end of the workshop. Lee began by presenting the audience an image of an emergency checklist for an airplane. He then posed the question: Is availability of the checklist a sufficient condition for making it safely onto the ground? After members of the audience answered that it would not be sufficient, he asked, "What else would you need?" This question framed the remainder of Lee's presentation. He pointed out that, just as an aviation checklist is not a sufficient condition for safely flying or landing a plane, an audit checklist is also not a sufficient condition for establishing, managing and maintaining a trustworthy repository. A good checklist can provide extremely valuable support for knowledge transfer, professionalization, instruction, verification and evaluation, by succinctly summarizing appropriate professional practices and lessons (which may have taken many years and many individuals to develop and refine). There are very good reasons why pilots keep checklists in the cockpit and consult them during various phas es of a flight. However, a checklist will never take the place of appropriate institutional strucutres, routines and commitments; or the skills, habits, insights, problem solving and collaboration of experienced professionals. When faced with an emergency situation, a pilot must often draw on the above resources to act immediately, then consult the emergency checklist (as a memory aid and verification tool) after the situation has been stabilized. In short, it's a checklist, not a do list.

Current environment and trends

The content of the presentations suggested that it is a perfect time to be asking the fundamental questions raised in the workshop call for papers. On the one hand, there is an urgent need to inform the increasing amount of institutional repository planning and development. On the other hand, most institutions are not yet locked into specific answers. According to Markey's presentation, 51% of respondents were not yet planning and only 10% had implemented an institutional repository. LeFurgy explained that there is also a wide diversity of approaches, even by those apparently doing same things. Lee suggested that this is analogous to the timing of the development of the OAIS, at a time when "actors within several streams of activity related to digital preservation perceived the need for a high-level model but had not themselves developed one" and " several actors now felt they had knowledge from their own recent digital archiving efforts, which could inform the development of the OAIS" (Lee, 2005). Workshop presentations also raised important points related to metadata creation and harvesting. Efron's found that there were a relatively small number of items in institutional repositories but relatively rich description of the items. Speakers suggested that there is already a lot of metadata sharing and federation taking place, but a pressing need for more sharing and federation of content.

What are the most promising approaches for implementing the attributes of the RLG-NARA Audit Checklist?

In the case of institutional repositories in academic environments, Markey and Kim both suggested that it might not be faculty or students who directly serve as the main Producers (i.e. submitters) of content. Lynch cautioned that information professionals should be careful not to neglect the substantial body of research being conducted outside of "big science."

Many of the lessons from the workshop speakers related to system architecture and sustainability. In the long-term management of digital collections, it is important not to assume the permanence of any specific hardware or software; Moore and Smith discussed the promise of various forms of virtualization, and Markey reported on respondents' plans to migrate institutional repository within four years.

The workshop also addressed promising ways to structure and coordinate work on digital repositories. Thibodeau elaborated benefits of addressing archival issues as a foundation for other systems within a cyberinfrastructure. Speakers explored various promising efforts to generalize and share products, including open source software licenses; user and developer communities, e.g. DSpace, Fedora, Virtual Data Center (VDC); common modular and extensible tools, e.g. JSTOR/Harvard Object Validation Environment (JHOVE), Storage Resource Broker (SRB); the Global Digital Format Registry (GDFR); joint efforts to support small players, e.g. OhioLINK; and building guidance documents from other existing documents, e.g. the Task Force on Digital Archiving Report, OAIS, Attributes of Trusted Digital Repositories. It is also important to share copies of digital objects in order to ensure redundancy, which will require architectures to support federation (e.g. SRB) and policies for collection sharing in cases when institutions have collections of very different sizes (Donakowski). One of the potential tensions in priority can between building services directly into applications being used by data producers (e.g. NARA’s Records Management Services) or instead moving data out of live systems in order to reduce risks associated with lock-in an obsolescence. For example, Lynch stated that learning management systems are "dreadful places to archive," so it is risky to depend on them for implementing digital curation requirements. Several speakers emphasized that one should not only write or follow rules but should also provide evidence for compliance with the rules (Dale; McHugh; Moore and Smith; Strathmann). Finally, Efron raised a fundamental point that can often be overlooked in discussions of repository trustworthiness: make sure your XML is well-formed.

Lee ended his presentation with "Issues for Future Research or Things to Think about on your Trip Home," which were based on selected evocative points or quotations from the spoken remarks of workshop contributors. These included:

  • “Do I document everything I do, or do I actually do my job?” (Dale)
  • Similarities/difference in the kinds of file format commitments that IRs are making (Lynch), or more broadly, defining appropriate levels of service (LeFurgy)
  • Institutional repositories and repository certification constitute “a semantically confusing scene” (Dale). For example, “different people have rather different definitions" of IR (Lynch). Should IRs be defined in terms of libraries or repositories (Lynch, Jones)? Should data centers and e-print servers be considered IRs? Has IR come to mean only repositories in which an academic library is taking an active role? Is there a required set of user services? Is IR synonymous with “ collecting archive” (Ambacher)?
  • There is a need to better clarify the level of granularity of both requirements and assertions about compliance with requirements (Dale, Smith, Moore)
  • What counts as trustworthy curation (inspired by Lynch)? Should the criteria focus primarily on digital objects (management of objects, metadata) – e.g. “DATA PASSable” (Crabtree & Donakowski) -- or primarily on communities of maintainers and contributors? Should certification be hard to obtain or simply documentation of contextual decisions or systems (Dale, Ambacher)?
  • Lynch raised several measurement issues. "There's no standard stuff count,” which can hinder planning and comparison, though statements about relative size are still useful (e.g. twice as much as last year). Digital preservation is a “metric that's defied measuring,” though the current working metric appears to be: "Well, we haven't lost much yet."
  • What constitutes success? According to Thibodeau, "you absolutely have to contextualize it"; and he suggests three axes for doing so: orientation, coverage, collaboration. If contribution is a success factor, what are the primary incentives (Kim)? According to LeFurgy, “retention of significant properties is a critical, but elusive, measure of success.” LeFurgy emphasized the idea of "acceptable loss rates." Strathmann emphasized the "adequacy principle," while Ambacher emphasized cases in which loss should be seen as a failure.
  • Does creation of appropriate metadata actually result in trustworthiness? Efron pointed out that data is lost when repositories include qualified Dublin Core, as harvesting of the metadata through the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) results in unqualified Dublin Core. Will this cause problems for users/applications in understanding (and trusting) data values? What and how much contextual information is needed for trust of data (Gewirtz)?
  • "Well-managed research never fails" because it always results in new information (Thibodeau).

Special Issue of JODI

The authors of the Workshop papers have all provided copies of the papers, and they are publicly available through the Papers and Presentations section of the Workshop web site. Many parti cipants also encouraged us to pursue a publication venue that would allow a subset of interested authors to further develop, expand and disseminate the their workshop products. Cal Lee and Helen Tibbo approached Cliff McKnight with the idea of a special JODI issue on Digital Curation and Trusted Repositories, and he graciously accepted this proposal. We hope that readers will agree that the 10 papers in this issue are valuable contributions to the evolving professional discussions regarding digital curation, and the management, evaluation, audit and certification of repositories.

Given the rapidly evolving nature of current work on certification and audit, it is important to read the papers in this issue within the context in which they were written. The RLG-NARA Audit Checklist was then the most widely recognized English-language guidance document, and several of the Workshop papers built directly from the Checklist. Since then, the Center for Research Libraries has taken responsibility for carrying on the effort and has recently published the revised and expanded Trustworthy Repositories Audit & Certification (TRAC): Criteria and Checklist. In December 2006, nestor released an English-language version of the Catalogue of Criteria for Trusted Digital Respositories (Dobratz et al 2006). DigitalPreservationEurope and the DCC have created a risk-based approach to audit and certification called DRAMBORA (DPE and DCC 2007). The CRL, DCC and certification working group of nestor are each attempting to establish audit processes for their own localities (US, UK and Germany, respectively). These three groups, along with DigitalPreservaitonEurope, have been collaborating to find points of commonality, as well as regional differences, in their complimentary efforts -- see e.g. the Core Requirements for Digital Archives (2007). A working group was also recently formed to produce an ISO standard for audit and certification of digital repositories.

Many of the authors of this special issue have led and contributed substantially to these recent developments. Several of the research studies represented in this special issue have also generated important further products and findings in recent months, and we encourage interested readers to be on the lookout for further publications from those efforts.


We would like to acknowledge the University of North Carolina at Chapel Hill School of Information and Library Science and University Libraries for sponsoring the JCDL workshop, and Carolyn Hank and members of the Program Committee for helping us to make the workshop such a success. The authors of the pieces in this special issue deserve recognition for their numerous insights and contributions, as well as their patience throughout the production, review and editorial process. We would like to thank Cliff McKnight, Scott Phillips and Anita Coleman for their considerable support and assistance in moving the special issue from conception to final product.


Brophy, P., and Frey, J. (2006) "Digital Curation Centre Externally Moderated Reflective Self-Evaluation Report". Digital Curation Centre.




Charter on the Preservation of the Digital Heritage. (2003) United Nations Educational, Scientific and Cultural Organization.

Core Requirements for Digital Archives. (2007) Digital Curation Center, DigitalPreservationEurope, NESTOR, and Center for Research Libraries.

DELOS Preservation Cluster.



Digital Curation and Trusted Repositories: Seeking Success.

DigitalPreservationEurope (DPE) and Digital Curation Centre (DCC) (2007) DRAMBORA: Digital Repository Audit Method Based on Risk Assessment. Draft.

Digital Repository Audit and Certification Working Group.

Dobratz, S., Hänger, A., Huth, K., Kaiser, M., Keitel, C., Klump, J., Rödig, P., Rohde-Enslin, S., Schoger, A., Schröder, K., Strathmann, S., and Wiesenmüller, H. (2006). Catalogue of Criteria for Trusted Digital Repositories, Version 1. Frankfurt, Germany: nestor Working Group on Trusted Repositories Certification.


Dublin Core Metadata Initiative.

Fedora. “The Fedora Project: An Open-Source Digital Repository Management System”,

Fitzgibbon, A., and Reiter, E. (2003) "Memories for Life: Managing Information Over a Human Lifetime. Grand Challenges in Computing - Research, edited by In Tony Hoare and Robin Milner (Swindon, UK: British Computer Society), pp. 13-16.

Garrett, J. and Waters, D., ed. (1996) "Preserving Digital Information: Report of the Task Force on Archiving of Digital Information." (Washington DC: Commission on Preservation and Access and Research Libraries Group).

Giaretta, D. (2006) “CASPAR and a European Infrastructure for Digital Preservation”, ERCIM News Online Edition, Vol. 66.

Hedstrom, Margaret, ed. (2003) It's about Time: Research Challenges in Digital Archiving and Long-term Preservation: Final Report on the NSF Workshop on Research Challenges in Digital Archiving and Long-Term Preservation, April 12-13, 2002. (Washington, DC: National Science Foundation & Library of Congress).

Hedstrom, M. and Ross, S. (2003) Invest to Save: Report and Recommendations of the NSF-DELOS Working Group on Digital Archiving and Preservation. Prepared for the National Science Foundation’s (NSF) Digital Library Initiative & the European Union under the Fifth Framework Programme by the Network of Excellence for Digital Libraries (DELOS).


Joint Information Systems Committee. (2003) "An Invitation for Expressions of Interest to Establish a New Digital Curation Centre for Research intoand Support of the Curation and Preservation of Digital Data and Publications".

LDB. Centre for Long-term Digital Preservation.

Lee, C. A. (2005). Defining Digital Preservation Work: A Case Study of the Development of the Reference Model for an Open Archival Information System. Unpublished PhD Dissertation, University of Michigan, Ann Arbor, MI.

Lee, C., Tibbo, H., and Schaefer, J. (2007) "Defining What Digital Curators Do and What They Need to Know: The DigCCurr Project." Proceedings of the 7th ACM/IEEE Joint Conference on Digital Libraries, Vancouver, British Columbia, Canada, June 18-23 , 2007, edited by Ron Larson, Edie Rasmussen, Shigeo Sugimoto, and Elaine Toms (New York: NY, ACM Press), pp. 49-50.

Levy, D. M. (1998) "Heroic Measures: Reflections on the Possibility and Purpose of Digital Preservation." In Digital libraries 98: the Third ACM Conference on Digital Libraries, June 23-26, 1998, Pittsburgh, PA, edited by I. H. Witten, Robert M. Akscyn and Frank M. Shipman (New York, NY: Association for Computing Machinery), pp. 152-161.

Library of Congress. National Digital Information Infrastructure and Preservation Program.

LOCKSS. Lots of Copies Keep Stuff Safe.

METS. Metadata Encoding and Transmission Standard. Library of Congress.

Nestor. Network of Expertise in Long-term Preservation of Digital Resources. 

NSF Cyberinfrastructure Council. (2007) "Cyberinfrastructure Vision for 21st Century Discovery". (Arlington, VA: National Science Foundation).

PLANETS – Digital Preservation Research and Technology.

Potter, M. (2002) “Researching Long Term Digital Preservation Approaches in the Dutch Digital Preservation Testbed (Testbed Digitale Bewaring)”. RLG DigiNews, Vol. 6, No. 3.

PREMIS. Library of Congress. Preservation Metadata Maintenance Activity.

PRESTO: Preservation Technology for European Broadcast Archives.

PrestoSpace. Preservation Towards Storage and Access. Standardised Practices for Audiovisual Contents in Europe.

“Reference Model for an Open Archival Information System (OAIS) CCSDS 650.0-B-1 Blue Book” (2002). Consultative Committee for Space Data Systems.

RLG and NARA. (2005) An Audit Checklist for the Certification of Trusted Digital Repositories, Draft for public comment (Mountain View, CA: RLG).

RLG-OCLC Digital Archive Attributes Working Group. (2002) “Trusted Digital Repositories: Attributes and Responsibilities. An RLG-OCLC Report” (Mountain View, CA.: RLG).

Ross, S. (1998) Changing Trains at Wigan: Digital Preservation and the Future of Scholarship, The JISC/NPO Digital Preservation Workshop, 3-4, March 1998, Scarman House, University of Warwick. ( Also at:

Rothenberg, J. (1995) “Ensuring the Longevity of Digital Documents”. Scientific American, Vol.272, No. 1, 24-29.

Rusbridge, C., Burnhill, P., Ross, S., Buneman, P., Giaretta, D. Lyon, L., and Atkinson, M. (2005) “The Digital Curation Centre: A Vision for Digital Curation”. From Local to Global: Data Interoperability – Challenges and Technologies, Mass Storage and Systems Technology Committee of the IEEE Computer Society, (June 20-24, 2005, Forte Village Resort, Sardinia, Italy).

Slats, J. and Verdegem, R. (2004) “Practical Experiences of the Dutch Digital Preservation Testbed”, VINE (The Journal of Information and Knowledge Management Systems) Vol. 34 No. 2, 56-65.

SRB - Storage Resource Broker. San Diego Supercomputer Center.

The State of Digital Preservation: An International Perspective. (2002) Washington, DC: Council on Library and Information Resources.

Tibbo, H. (2003) “On the Nature and Importance of Archiving in the Digital Age” Advances in Computers, Vol. 57, 1-67.

Trustworthy Repositories Audit & Certification (TRAC): Criteria and Checklist. (2007) (Chicago, IL: Center for Research Libraries; Dublin, OH: OCLC Online Computer Library Center).

van der Werf-Davelaar, T. (September 1999) “Long-term Preservation of Electronic Publications: The NEDLIB Project”. D-Lib Magazine Vol 5, No. 9.

"What is Digital Curation?” Digital Curation Centre.