Digital Preservation

Some strategies proposed by archivists on how to preserve media on computers:

Technique Description Pros Cons
Migration Periodically convert data to the next-generation formats Data is instantly accessible Copies degrade from generation to generation
Emulation Mimicking the behavior of older hardware with software, tricking old programs into thinking they are running on their original platforms Data does not need to be altered Mimicking is seldom perfect; chains of emulators eventually break down
Encapsulation Encase digital data in physical and software wrappers, showing future users how to reconstruct them Details of interpreting data are never separated from the data themselves Must build new wrappers for every new format and software release; works poorly for non textual data
Universal virtual computer Archive paper copies of specifications for a simple, software-defined decoding machine; save all data in a format readable by the machine Paper lasts for centuries; machine is not tied to specific hardware or software Difficult to distill specifications into a brief paper document  

The first two methods preserve a technological environment while the second two overcome the obsolescence of the file format.