How do you know if they're worth preserving or not if you can't see them? And "worth preserving" is a term that can be seen from a myriad of perspectives. Whet

How do you know if they're worth preserving or not if you can't see them? And "worth preserving" is a term that can be seen from a myriad of perspectives. Whether it's good or not is only one factor. A film or television episode might be worth preserving because: * it's an early work or appearance by someone who would go on to be significant * it's a product of its era displaying the context, fashions, language, politics, events and attitudes of the time * it's actually really bad, but demonstrates what bad film-making looked like in that time * it's a cherished childhood memory of someone who mentions that in their autobiography, and so scholars may wish to have access. Probably loads of other reasons why something is worth preserving beyond a basic question of "is it any good?". The BBC destroyed and disposed of a large number of episodes of Doctor Who from the 1960s, and a lot of time and effort has been put into recovering and restoring copies of these because they are a part of the ongoing narrative of the evolution of British television.