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| Preservation > Computer > Best Practices |
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Computer-based art is among the most ephemeral of art forms. Not only are media files subject to rapid obsolescence, but the software, hardware, and operating systems needed to play back these files have short lives as well. Present-day systems can become technology of the past in just a few years, potentially sentencing an important work to a premature death. Around the world, artists, programmers, archivists, and conservators are working to create strategies for the preservation of this vital art. A number of major initiatives are tackling questions of documentation, authenticity, preserving the artists' intent, and other critical issues. But the preservation of computer-based art is still a young field. Though it draws upon practices and philosophies used by art conservators for decades, digital preservation does not always have clearly defined standards and practices-in part because of the newness of this medium and in part because of the widely divergent works that fall under the heading "computer-based." Thus the document that follows cannot be considered a "Best Practices" document in the strictest sense of the word. There are no strictures or "musts" here-only basic principles that will help determine the best course of action for each situation. This document is a work in progress-designed to lay out the fundamental questions these works raise, and to gather the most recent research in the field. Documentation Documentation is the process of gathering and organizing information about a work-including its condition, its contents, and the actions taken to preserve it. The interactive nature of much computer-based art means that its documentation calls for a broader range of data than that of single-channel video works or conventional films. Cataloging requires not only gathering data about the digital files that make up the work-what is known as metadata-but also information about the work's behavior-what it actually does. Behavior Computer-based art that is interactive or time-based has unique behaviors that must be documented if the work is to be preserved accurately. The ideal way to document behavior starts with the artist. Conducting an artist's interview or questionnaire is becoming increasingly common practice in collecting institutions. These interviews include such questions as:
This information will be critical in the event of obsolescence of an artwork's original media. Another useful component of documentation is how an audience interacts with a work. Interviewing audience members, recording screen shots with still photography or video, copying a work's directory and subdirectory structure, and using diagrams or a brief narrative to summarize particular interactions or exchanges with the work are all helpful for future implementation. (Keep in mind that this kind of documentation adds its own preservation needs.) Other forms of documentation are important as well. Collect ancillary materials related to the creation, exhibition, and critical reception of the work, such as exhibition guides, press books, or photographs of the installation or exhibition. For additional information on documenting new media and computer-based art, and currently developing description standards and schema, take a look at the V2_Organisation's Capturing Unstable Media project, the Danube University Krems' Database of Virtual Art, the Guggenheim Museum's Variable Media Network, and Rhizome's ArtBase. Metadata Metadata, as mentioned above, is data about data, documenting technical information about a digital file-everything from the basics such as creation, date, and file format to detailed information on codecs, compression, etc. While the documentation strategies above are being developed within the art world, metadata is equally important to libraries, archives, businesses, government agencies-any entity dealing with critical information in digital form. It is groups like these that have driven metadata standards and schema. However, in the world of digital art: Keep in mind that apart from format and hardware obsolescence, human error and poor management of files is the largest risk factor in preserving digital works. It is essential to capture data about the files and their location carefully and consistently in order to ensure their longevity. In order to obtain thorough documentation of the diverse, intricate, and interdependent components that make up these works, it is essential to make an item-level inventory of each moving-image file or audio file, as well as the software, hardware, and operating system needed to run the file. Of equal importance, each component record associated with the artwork must be related to one another in the database in order to identify all parts of a single work. This can be done by creating a unique identifier for the work and using variants of this number for each of the individual parts. A "work" record describing the content of the work should be created, with individual item records for the individual files linked to it. Separate item-level records for files are necessary because digital files will have different technical metadata and creation information. If there are several versions of digital files (for example, working and final files), the data record must identify which file is the final or "authentic" file to be used in re-creating or displaying the work. In general, metadata can be divided into four general categories: descriptive (describing the content of the work); technical (describing the technical creation of the file and requirements for playing the file); preservation; and administrative (includes how the work was acquired and rights information). The lists of fields below will give an idea of what each category entails-and just how much data about a file it is necessary to capture. Descriptive (The descriptive data should make up the "work" record; the information contained in this record is applicable to all versions of the digital file.)
Technical
Preservation
Administrative
General Recommendations Naming Files When creating each file, follow the established naming conventions and make sure to include the file extension. These conventions should be decided upon at the beginning of the project. The file name could be based on the unique identifier. What is most important is that the file name be unique, not duplicated in any other project or elsewhere on your servers. Do not give the files basic and potentially duplicative names (e.g., 001.tif, 002.tif, etc.). Equipment and Media Labeling Hardware devices to play back, record, and store works-such as hard drives, Zip drives, and monitors-can be secured with archival artifact identification tags. Portable storage devices such as floppy disks, Zip disks, or optical discs can be secured with acid-free labels, which indicate the unique identification number of the corresponding work. Keep in mind that the adhesive on labels can dry out and the labels can fall off. Optical media such as CDs or DVDs should be stored in polypropylene jewel cases with acid-free labels. A work's unique identifier should be written on the clear plastic inner hub of the disc with an archival soft felt-tip, non-solvent, water-based, permanent ink marker. Container labels should include the following information:
Inspection Inspection is the process of gathering detailed information about a file, in preparation for migration to new formats, as well as to check the status of works already preserved or yet to be preserved. In the analog realm, works are regularly inspected in order to detect signs of deterioration in the physical objects. In the context of digital media, inspection of elements consists of checking regularly for operability. It is important to ask, for example, if the software and operating system are functional and still able to maintain the integrity of the work. These kinds of inspection tests cannot be performed without the appropriate hardware. Hardware devices also need to be inspected for operability to ensure that equipment is fully functional. Inspection reveals what conservation and preservation actions are needed. The following characteristics or basic attributes of computer-based artwork should be examined and described in the catalog during inspection:
Ongoing Inspection Rapidly changing technologies and the threat of obsolescence necessitate regular inspection and evaluation of the integrity of a computer-based artwork-the work as an interoperable system of data, data formats, software, and physical hardware. It is hard to quantify how often items should be inspected. Often, software upgrades do not provide backward compatibility, thereby rendering large amounts of digital information obsolete in a short amount of time and without advance warning. Ideally, inspections are performed as regularly as every six months. This is not always feasible, of course, but when bringing a computer-based work into a collection, periodic inspection should always be considered as part of the institution's responsibilities toward the work. Test the work in its original environment as well as in the latest available environment using the newest version of software, operating system, and/or hardware. Retain multiple copies of the original software. These tests are good opportunities to assess preservation risks and consider what actions will be necessary when the work must be migrated. Data Storage Storing digital media on a system of redundant independent hard disks (such as RAID-6) or on a server duplicates your data and keeps it relatively secure, provided it is well managed. This is the most expensive option. As cost per megabyte has decreased, a single external hard drive is an affordable solution and is reliable enough to store the components of a digital work. Redundancy Redundancy is key, as drives can fail. It is recommended that you back up the work on at least two hard drives and leave one hard drive sitting on a shelf, preferably off site in case of disaster. Or even better, have multiple format redundancy: files on HDDs as well as files on tape. It is also wise to bring together files and outside links that may be spread over several servers and/or directories to maintain provenance of the work and exert more control over the individual components. This is an essential step in preserving websites. If your institution can afford to do so, it is also good to back up local data onto a computer storage magnetic tape format such as Linear Tape-Open (or LTO), which should be stored off site. This requires being networked into a local area network with tape backups. It is recommended that you store data on separate media that use different technologies so that your archive is not dependent on one technology. Removable storage devices should be kept consistently cool and dry and away from direct sunlight and strong magnetic fields. The air should also be free from dirt, dust, and chemicals. Inert polypropylene containers for external hard drives and optical discs offer additional protection. Store discs vertically in acid-free plastic jewel cases. Storage devices should be kept on a shelf when not in use. Leaving media in a drive for an extended period of time can cause heat and mechanical damage. Maintain collection security by making sure the original files are read-only and that a limited number of trusted conservators can access the original work. Copy the work onto recordable compact discs for access purposes. A note about "archival" gold DVD-Rs and CD-Rs: optical discs are vulnerable to scratches, heat, and humidity. They can delaminate in heat. Also, humidity can ruin a disc if moisture gets to the adhesive layer of a DVD-R through unsealed edges. Gold optical discs have a 24-karat reflective layer that is inert to oxidation and tarnish, and uses an organic phtalocyanine dye that, according to independent studies, has the longest lifetime of photosensitive dyes. The dye is subject to degradation over a long period of time, especially if the optical media is kept in a lighted area. The light can fade the dye, which causes failure when the laser tries to read the information that has been recorded to the disc. Equipment Storage Like hard drives and disks, computer equipment and monitors should be kept consistently cool and dry and free from airborne contaminants. Preservation Activities Preservation refers to the overall process by which the content of an item is saved and its long-term viability ensured. Migration-transferring digital information from one hardware and software setting to another-is inevitably part of the preservation process. Assessing the Risks: Triage Using an item-level inventory, assess each component in terms of risk of deterioration or obsolescence. Distinguish file formats as proprietary or open source. Who developed the standard, when, and who owns it now? What software is needed to read/view the file? Is the format still supported? Similarly, assess hardware requirements to "run" the work. Is the software application still supported? Are special installations or plug-ins required? What is the hierarchy and overall infrastructure of the work? What are the requirements for display? Describe the "look" of the work. What are the formal qualities (image content and image quality)? What are the artist's installation instructions? What is the functionality of the work? Describe the "feel" of the work. How does the user interact with the work? What are the variables? Focus initial preservation efforts on works that have physically deteriorated or include proprietary components that are no longer active or supported in the industry. Preservation Strategies Migration Migration (reformatting and refreshing) is a solution to media obsolescence or deterioration. There are several levels of migration. Maintaining the original integrity and functionality of the work, you can transfer hardware and software to a new operating system or you can transfer an obsolete file format to a new format. Emulation Emulation involves the re-creation of the technical environment required to view an object. This is achieved by maintaining information about the hardware and software requirements so that the system can be reengineered by future systems to emulate the original environment. This approach means you do not need to migrate files, but emulators must be created for every software and hardware configuration, which can be expensive. Encapsulation Encapsulation groups a digital object with all components that are necessary to provide access to that object. In encapsulation, physical or logical structures called "containers" or "wrappers" provide information about the relationships between all data and software application components. Encapsulation aims to overcome the issue of obsolete file formats by including details on how to interpret the original information and possibly re-create the original work. It is critical to document all preservation actions and experiments in the catalog. Although the archivist should avoid making changes that compromise the overall functionality or "look and feel" of the work, any changes that occur, if at all, should be thoroughly documented and explained. For more information on migration and other preservation strategies, see Cornell University Library's Digital Imaging Tutorial and the National Archives of Australia's digital preservation strategy.
Quality Control Ideally, image quality assessment should be conducted by the same person, using the same calibrated equipment and settings. Staff may need training to communicate image appearance effectively, in a balance of formal qualities and content. Test the behaviors and functionality of a work against the original. If the original is no longer accessible, test against documentation of the original. Technical variables affecting display include:
Initiatives and Resources A number of organizations and initiatives are doing vital work in the area of preserving digital art, including:
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