capacity of the STM & LTM

what is capacity?

the amount of information the memory store holds

what does research suggest about the capacity of the STM?

it suggests that STM capacity is limited to 7+ / -2 items (or between 5-9 units)

what happens when new information comes into STM?

it pushes out the old information (displaces)

why does new information push out (displaces) old information within the STM?

due to the STM’s limited capacity

who conducted research into the capacity of the STM?

Miller (1956)

what does miller’s research into the capacity of the STM support?

the idea of a limited capacity

what did miller use in his research in order to support the idea of a limited capacity within the STM?

the digit span technique

what is the digit span technique?

1. reading a series of digit sets that get progressively longer

2. the individual is asked to immediately repeat the digit set back in the right order

what did miller find regarding the digit span technique?

that participants could recall on average 7+ / -2 digits

what did miller conclude with his research into the capacity of the STM?

1. that STM has a limited capacity

2. thus, new information coming into STM displaces the old information

what does research suggest about the capacity of the LTM?

that it is unlimited

why is there very little research into the capacity of the LTM?

because capacity of the LTM is notoriously difficult to measure