Average shot lengths are usually measured in seconds. Some more contemplative films have average shot lengths that last minutes, as noted in the comments field of Unspoken Cinema's post on average shot length.
"ASL (Average Shot Length) indicates the average duration of a shot between cuts in a film (total film run time divided by number of shots). It's a data used to compare films from their editing style : how often do they cut, how long do the shots last. A long ASL means the film uses, on average, longer shots and fewer cuts. Comprehensive example of ASL calculation (at OffScreen) : Bresson's Pickpocket(1959) ASL = 10"
"In my book, THE WAY HOLLYWOOD TELLS IT, I try to show that the acceleration of cutting in recent decades can be seen as moving from an ASL range of 8-11 seconds before 1960 and towards a range of 4-6 seconds in recent years." David Bordwell
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