Nearly every museum in Canada has a growing collection of electronic media, including audiotapes, videotapes, CDs, and DVDs. Unfortunately, many of these media have poor survival characteristics. Information can be lost for a number of reasons.
The longevity of electronic media is affected by a variety of factors:
These multiple influences make it difficult to accurately predict survival rates.
The values presented in the accompanying table are rough estimates only. It is best to be conservative when predicting survival rates and to take action to preserve electronic media earlier rather than later.
Predicted longevity of electronic media
Media type
Predicted longevity
Magnetic disks
Hard disks
2–5 years
Floppy diskettes
5–15 years
Magnetic tapes
Digital
5–10 years
Analog
10–30 years
Optical discs
CD-RW, DVD-RW, DVD+RW
CD-R (cyanine and azo dyes)
Audio CD, DVD movie
10–50 years
CD-R (phthalocyanine dye, silver metal layer)
DVD-R, DVD+R
CD-R (phthalocyanine dye, gold metal layer)
>100 years
Other optical discs
MO, WORM, etc.
10–25 years?
Flash media
?
Technology is constantly changing. For example, it is now difficult to obtain a reel-to-reel tape recorder or an eight-track tape player, although these technologies were widespread only a few years ago. Likewise, the once very popular VHS videotape recorders and audio cassette players will probably become unavailable at some point in the future, as will CD and DVD players/drives.
Operating software is also in a constant state of change. Therefore, it is likely that the operating system software required to read electronic media collections, as well as the file formats for images, audio, video, or text information, will become obsolete.
There are some concrete steps that museums can take to improve the longevity of electronic media collections. Taking action now will make it much less likely that information will be lost in the future.
