First 317 words of the document:
Definition- memory for immediate events.
Duration- when rehearsal is prevented about 20 seconds, proved by
Peterson and Peterson in 1959. 24 university students were told by an
experimenter a consonant syllable followed by 3 digits e.g. WRT 303.
Immediately after being told this information the participant had to
count back from the number in groups of 3 or 4 to prevent rehearsal,
when told to stop they had to recall the consonant syllable. Each
participant was given 2 practice trials followed by 8 real trials on each
trial the time spent counting backwards was different e.g. 3,6,9,12,18
seconds. Participants remembered 90% when there was only a 3 second
gap but only 2% remembered with an 18 second gap.
Capacity- less than 7 chunks, this is shown by Joseph Jacobs in 1887. He
read out a list of numbers to people then asked them to recall the
numbers in the correct order, he found the average span for digits was
9.3 items, when he did the same thing for letters the results changed
only a 7.3 items average span was achieved, Jacobs believed this was
because there are only 9 digits but there are 26 letters. George Miller
found on average people find it easy to remember upto 5 items but
sometimes it can vary e.g. 7±2 this is because we chunk things together.
The size of the chunk affects the number of chunks you can remember
this was found by Simon in 1974, people found it harder to remember 8
word phrases compared with one syllable words.
Encoding- Acoustic or visual, this has been proved by Baddeley in 1966.
Participants were given lists of words that were either acoustically
similar or dissimilar, or words that were semantically similar or dissimilar.
He found participants had difficulty remembering acoustically similar
words in STM but semantically similar words caused no problems.