Schedules are commonly used to reduce anxiety in autistic children. Visual representations of key events called Picture Exchange Communication System (PECS) may be used to outline the sequence of a single task, lesson or a daily or weekly plan. Schedules usually consist of two columns, the schedule column and the "finished" strip.
Sequences are used to prepare for a change in routine and as a way to visually reinforce concepts. Change can be built into a schedule by using a "special activity" PECS symbol that identifies an unspecified or unexpected activity, which may occur in a general sequence of events.