Digital Collections and Archives: Preservation

Defining Digital Preservation

A common question is "just what is digital preservation?" While a common perception is that digital preservation is essentially just a backup (or multiple backups) of materials, digital preservation actually goes far beyond the concept of backups or a mere technical storage solution.  According to the JISC (Joint Information Systems Committee) article Digital Preservation: Continued Access to Authentic Digital Assets,

"Disaster recovery strategies and backup systems are not sufficient to ensure survival and access to authentic digital resources over time. A backup is a short-term data recovery solution following loss or corruption and is fundamentally different to an electronic preservation archive."

The American Library Association provides three definitions of digital preservation:

Short Definition

"Digital preservation combines policies, strategies and actions that ensure access to digital content over time."

Medium Definition

"Digital preservation combines policies, strategies and actions to ensure access to content that is born digital or converted to digital form regardless of the challenges of file corruption, media failure and technological change. The goal of digital preservation is the most accurate rendering possible of authenticated content over time."

Long Definition

"Digital preservation combines policies, strategies and actions to ensure the most accurate rendering possible of authenticated content over time, regardless of the challenges of file corruption, media failure and technological change. Digital preservation applies to content that is born digital or converted to digital form.

Digital Preservation Systems

Key components of a highly functional digital preservation system include: a database that tracks preservation actions taken on each content object to include recording events, agents and objects; active checking of the fixity on archived objects to ensure the integrity of archived materials; and alerts to archive managers of any unauthorized changes to archived materials. An excellent summary of digital preservation's core components can be found in the Digital Preservation Management Workshop and Tutorial initially developed and hosted at Cornell University.  Details of preservation activities required of a trustworthy digital repository and examples of how these requirements can be fulfilled can be found in the Trusted Digital Repositories: Attributes and Responsibilities along with the Trustworthy Repositories Audit & Certification(TRAC): Criteria and Checklist, which is intended to "develop criteria to identify digital repositories capable of reliably storing, migrating, and providing access to digital collections."  Digital preservation repositories can be certified as Trustworthy Digital Repositories (TDR) by the Center for Research Libraries, and self-certification of digital preservation repositories using the Trusted Digital Repositories: Attributes and Responsibilities and TRAC Criteria and Checklist are also encouraged.  The NDSA Levels of Preservation are a quick way to evaluate your organization's preservation efforts which offer "a tiered set of recommendations for how organizations should begin to build or enhance their digital preservation activities".

Digital Preservation Management

An excellent tutorial on digital preservation management developed by Cornell University provides an excellent overview on developing digital preservation programs. Digital preservation policies are a good idea to document an organization’s commitment to preserve digital content for future use, specify file formats to be preserved, the level of preservation to be provided, and ensure compliance with standards and best practices for responsible stewardship of digital information. Digital preservation strategies and actions address content creation, integrity and maintenance.  

Content creation includes:

• Clear and complete technical specifications

• Production of reliable master files

• Sufficient descriptive, administrative and structural metadata to ensure future access

• Detailed quality control of processes

• Use of persistent identifiers

Content integrity includes:

• Documentation of all policies, strategies and procedures

• Recorded provenance and change history for all objects

• Verification mechanisms

• Attention to security requirements

• Routine audits

Content maintenance includes:

• A robust computing and networking infrastructure

• Storage and synchronization of files at multiple sites

• Continuous monitoring and management of files

• Programs for refreshing, migration and emulation

• Creation and testing of disaster prevention and recovery plans

• Periodic review and updating of policies and procedures

Digital Preservation Glossaries

• Digital Preservation Coalition's Digital Preservation Handbook, Glossary
• National Digital Stewardship Alliance Glossary
• Florida Digital Archive's Glossary