The role of an assistant director on a film includes tracking daily progress against the filming production schedule, arranging logistics, preparing daily call sheets, checking cast and crew, and maintaining order on the set.
This was when the role was more general and encompassed all aspects of filmmaking such as set design and script editing.
It is more common now for an assistant director to transition to a theatre production management or producer role than to directing, with contemporary exceptions such as James McTeigue.
3ADs in Britain and Australia have different duties from a second second AD, and the terms are not synonymous.
Over the years, special procedures have been developed for this task to achieve maximum efficiency during shooting, which are usually some variant of the following: The above roll sequence can be varied by, for example, eliminating the sound calls and the clapping of the slate if the shot is mute or "MOS" ("MOS" is an abbreviation of unknown origin for shooting without sound).