Surprisingly, digital files can be much more difficult to maintain and preserve than analog formats. Most everyone has lost a computer or a hard drive, at some point. In the age of cloud storage digital storage can cause a false sense of security. When digital files first came into widespread use, many people saw it as a solution to the problems of preservation. Digital files were not sensitive to light, heat, hand prints or humidity. However, after many years of use, it has become clear that digital files have many inherent issues that are difficult to manage and can lead to serious loss of important information if not managed well.
The problem of archiving and preserving electronic records is serious issue that many people across the country have been attempting to address. Because formats constantly change, digital files are susceptible to security issues and corruption. We are creating an incredible amount of digital files every day, a volume that has quickly surpassed anything that was created in previous areas. The Internet Archive is doing interesting work on this issue, particularly in preserving websites, but this type of archiving is still in development. There are a few steps you can take with personal files to ensure their long-term integrity, and if you are transferring analog media into a digital format, there are a number of recommendations that you should keep in mind.
There are a few important principles to remember in digital file storage. Replication, migration, and metadata are three of the most important to [rinciples to preserve histories.
One of the most important digital repositories used in libraries is a system called LOCKSS, which stands for Lots of Copies Keeps Stuff Safe. They specialize in journals, but the idea can be applied to any times of digital documentation. Do not store everything on one computer or one hard drive, have some copies on solid state drives and some in the cloud, and make sure to keep the multiples in different places (in case of flood, fire or other natural disaster).
It is the nature of digital files that formats become obsolete. In the 1980s and 1990s, Word Perfect was used every. Today it is very difficult to open a file on a new computer that was created in .wpd. This example illustrates a common problem with digital files that has not yet been resolved. By assessing the current formats of all of your files and migrating those that are on the verge of being obsolete, you will avoid attempting to open something long after it can no longer be used. Microsoft and other similar software companies tend to support the use of older formats for at least ten years, but this cannot be guaranteed going forward. It is also important to be mindful of using proprietary software that cannot be read by other formats. While we may believe that Microsoft will always be a powerful force in business, and Microsoft Word will always be the primary software for document creation, this is unlikely to be true. While the process of migration is time-consuming and tedious, it will protect those files.
Metadata is data about data, an important set of information that can show a wide variety of important details. There are three types of metadata, structural, descriptive, and administrative. Structural metadata describes how a format is put together. Descriptive metadata describes the author, title, etc. and explains the content of the data. Administrative metadata shows when a document was created, by whom, and who has access to it. These three types of metadata can either be created by the program when you create the file, or can be created and stored by the user. All of this metadata can be exported and managed in a file management system. In a small institutional or personal archive, metadata should be seen as a tool that you can use to your advantage, not another difficult and complicated technical problem. Most programs automatically create metadata that you can search and organize. The most important element of metadata is to be consistent and honest about all changes.
The Research Library Group and The Online Computer Library Center (OCLC) came together in 2000 to develop the Trusted Digital Repository Model, which provides a set of rules for digital repositories. They also developed the model for the Open Archival Information System (OAIS). These systems are complex, but will provide more context for how this work is being done in professional archives.
Digital preservation is an evolving field, but personal archiving is an area that is getting an increased amount of attention. There are a number of resources for digital file management that will provide more details and give information about conferences that deal with these issues.
For more information:
Digital File Types for Long-Term Storage
These file types are recommended by the Library of Congress for long-term storage.
JPEG-good for online access, easily compressed
TIFF-best for a preservation master, very large file
WAVE-can be uncompressed or compressed, widely adopted
MP3-good for access
PDF-best for storage of completed files, cannot be edited
DOCX-widely adopted format, but can be changed so best to password protect
Video is particularly difficult because the files have both a codec and a wrapper, Audio Visual Preservation Solutions gives a good overview of the meaning of a video formats here.
MPEG-4- supports a few codecs, but they are useful
Quicktime-supports many codecs
MXF-Library of Congress is using this container
MOV-Many archives have adopted this container as it is widely available
For more information on file formats: