Guides

First Steps in Preserving Digital Publications

Cover of pamphlet

The purpose of this brochure is to assist libraries to manage their collections of physical format digital publications. The National Library of Australia has been working on preservation strategies for this category of publication for some time, and now we seek to share our experience and expertise.

What Are Physical Format Digital Publications?

Physical format digital publications are those issued on media such as floppy disk and CD-ROM. This material constitutes a growing component of Australian publications. The machine-dependent nature of digital publications requires particular preservation strategies to ensure that they remain accessible.

Need for Action

Digital format publications provide an intellectual record of our national cultural heritage in the same manner as other forms of publication. Electronic material often provides enhanced functionality not available through the use of paper.

Media instability and changes in technology are the two main threats to the continued accessibility of both floppy disks and CD-ROMs. The physical lifetime of floppy disks has been estimated at between five and ten years. CD-ROMs are a current and popular technology in a relatively stable format compared to floppy disks. Independent analysts report that compact discs (CDs) could last between ten and 100 years. However, both floppy disks and CD-ROMs will be subject to changes in technology, which may render them inaccessible within a much shorter time span. In five years, we may not be able to retrieve some information stored as digital media, and this will certainly be a problem within 50 years.

Steps to Take

Know Your Collection

Preservation of electronic media poses many challenges. Although definitive solutions are not yet available, there are a few simple steps that can be taken to help manage your collection.

It may be necessary to conduct a survey of your collection to discover what range of formats currently exist and how many are already effectively inaccessible. To identify electronic material currently in your collection, try searching the General Material Designation (GMD) of the catalogue record for common terms such as floppy disk, computer file, CD-ROM, optical disc, etc. Some items will inevitably be missed, especially electronic material accompanying print formats. Shelf checks of your collection may reveal further items. It is helpful if staff are made aware of this material and its preservation requirements.

Decide on what you wish to keep, based on your collection development policy and your knowledge of the collection. In general, normal criteria will apply when setting priorities; however, action will need to be taken within a much shorter timeframe than for print. It may be useful to focus on the most vulnerable media, such as the floppy disks in your collection, especially those in the near obsolete 5 1/4" format.

Record Preservation Information

It is important to record preservation information (i.e. metadata) relating to the system requirements of the material, and to use a standard vocabulary when describing hardware and software requirements.

The system requirements of this material, including digital media accompanying printed publications, need to be recorded in a way that allows efficient searching and retrieval of the metadata. This information may be recorded in the general note area of the MARC record.

The NLA recommends following guidelines such as AACR2 and the International Standard Bibliographic Description for Electronic Resources. But it should be noted the level of detail which needs to be recorded for material for preservation is generally greater than the specifications in those guidelines, eg AACR2 use the term computer optical laser disk instead of CD-ROM or DVD-ROM, which is vital information for the use and preservation of these disks.

Storage

Storage and environmental conditions can have a significant impact on the life of digital media. While CDs and floppy disks can tolerate a fairly wide range of conditions without sustaining immediate damage, constant temperature and relative humidity slows down the process of physical deterioration. Ideally, physical format electronic material should be stored in a dust-free environment, with stable temperature and relative humidity (below 20 degrees Celcius, relative humidity 40 per cent).

Keep tapes and diskettes away from magnetic fields. For example, do not store floppy disks or tapes near electrical equipment or on motorised shelving. Diskettes and CDs should be placed in individual boxes immediately after use to avoid dust and possible damage. It may be easier to manage this material if it can be stored separately from the rest of the collection.

Handling

The worst handling stresses for an optical disc are caused by severe flexing or the application of a sharp point to either surface. Pens or pencils should never be used to write on optical discs. If it is necessary to write on a CD, a soft felt-tip marker is preferable to other writing instruments, but with some solvent-based markers there can be a danger of the solvents migrating into the protective layer. If a CD must be marked, it should be done in a way that is approved by the disk manufacturer.

Applying labels of any kind can upset the balance of an optical disc, making it difficult for the player to read. Also, labels may peel in humid conditions. Once a label has been placed on an optical disk, however, it is especially important not to try to remove it. The act of peeling off a label creates a lever action that concentrates stress in a small area. Such stress can cause delamination.

Observe any manufacturers recommendations regarding the handling of magnetic and optical discs. See Edward P. Adcock, IFLA Principles for the Care and Handling of Library Material (International Preservation Issues, no.1) (Paris: IFLA-PAC, 1998).

Security

Because of their small size, disks are relatively easy to steal. To minimise this likelihood, ensure that staff rather than users handle the material, or insist that some form of identification be held at the user desk until the disk is returned.

If security tags are used, place them on the container rather than directly onto the CD or floppy disk. Lockable storage containers are also available, though costly. In general, we suggest that digital media be stored in a separate area, with restricted access.

Copyright

Copying is a major component of a preservation strategy. Ideally your library should contact copyright holders individually to gain permission. The Copyright Law Review Committee (http://www.agps.gov.au/clrc/) recommends making backup copies for preservation purposes.

The National Library has decided that it may make backup copies for preservation purposes, unless this is clearly prohibited on the packaging, or unless the Library has signed an agreement to the contrary with the copyright owner.

Longer-term Options

The National Library of Australia has made a commitment to pursue long-term solutions for the preservation of physical format digital publications. Strategies are set out in a proposed research agenda, which is being pursued with the help of the State Libraries. However, we welcome contributions from any interested party. A copy of the research agenda can be accessed at

http://www.nla.gov.au/policy/rsagenda.html

We are considering a number of options for ensuring long-term access. These fall broadly into four strategies:

Refreshing

Periodically copying the data onto a newer carrier of the same type (e.g. recopying floppy disks onto new floppy disks). This is a short-term strategy that goes part way to addressing the problem of media instability, but it is resource intensive and does not address the problem of technological obsolescence.

Transfer

Copying data onto a more stable carrier (e.g. transferring data from a floppy disk to a writable CD, known as a CD-R). This is a short- to medium-term strategy, but it still requires the CD-R to be migrated when the technology changes. For a limited number of publications, where there is no loss of functionality, printing the material to paper may be a viable option.

Emulation

Using emulation software to provide access to programs across different platforms. For example, a Commodore 64 emulator can be used to run a program on a PC. Emulation is in the developmental stage and appears to hold more promise for items not suitable for migration. It may not be possible to rely on emulators, especially for less common file formats. Emulation also requires some from of refreshing or transfer to more stable media for long-term storage.

Migration

Periodically transferring digital material from one hardware/software configuration to another, or from one generation of computer technology to a subsequent generation. Migration differs from refreshing or transfer as a means of digital preservation in that it tries to copy publications to different media and across different platforms. It may not be possible to retain the "look and feel" of some publications through subsequent migrations.

It is likely that no one option will provide all the solutions to the preservation of digital format material, and instead a combination of options will eventually be employed.

The National Library regards it as essential that a collaborative approach between creators, publishers and collectors of electronic publications be adopted when considering issues and conditions of long-term access.


For further information see:

Top

About This Site | Copyright | Privacy | Accessibility | Site Map | Site Search | Content A-Z | Contact Us