CODING, CAPACITY AND DURATION OF MEMORY
Coding: CODING CAPACITY
The format in which Once information gets Jacobs used the digit span technique and found the average digit span was
information is stored in into the memory 9.3 items for digits and 7.3 items for letters. Jacobs suggested that this is
the various memory system, it is stored in because there are only 10 digits but 26 letters. Miller reviewed this research
stores. different formats and came up with the 7+/-2 theory with capacity of STM. They found 5 words
Capacity: depending on the is as easy to remember as letters (chunking).
The amount of memory store. The
information that can be process of converting DURATION
held in a memory store. information from one LTM: Bahrick et al asked people of various ages to put names to faces in their
Duration: form to another is high school yearbook. 48 years on people were 70% accurate when they had a
The length of time called coding. picture as a cue (better recall when a cue was given). It shows how memories
information can be held stored in the long term memory has no known capacity.
in memory. Baddeley got
participants to STM: Peterson and Peterson showed 24 students a nonsense trigram followed
remember a list of by a three digit number. They had to count back from this name in 3s or 4s (to
Short term memory: words, read out one prevent rehearsal) and were then asked to recall the trigram. Participants
The limited capacity per second and then remembered about 90% when there was a 3 second gap and 8% with a 18
memory store. Coding recall them in order. second gap.
is mainly acoustic, List A had
acoustically similar Evaluation:
capacity is between 5 1. Artificial stimuli - one limitation of Baddeley’s study is that it used artificial stimuli rather than
and 9 items and words. List B had meaningful material. The word lists had no personal meaning to the participants. That means we
duration is between 18 acoustically dissimilar should be cautious when generalising the results to different kinds of memory tasks.
and 30 seconds. words. List C had 2. Lacking validity - one limitation of Jacob’s study is that it was conducted a long time ago. Early
semantically similar research in psychology often lacked adequate control e.g. some participants may have been
Long term memory: distracted whilst they were being tested so didn’t perform as well as they might have. This means
The permanent words. Group D had there were confounding variables that were not controlled.
memory store. Coding semantically 3. One limitation of Miller’s research is that he may have oversized the capacity of the STM. Cowan
is mainly semantic, it dissimilar words. The concluded the capacity of STM was only about 4 chances, suggesting the lower estimate of Millers
results showed that estimate (5 items) is more accurate.
has unlimited capacity 4. Meaningless stimuli in STM study - a limitation of Peterson and Peterson’s study is that the
and can store memory STM is mainly stimulus material was artificial. Trying to memorise consonant syllables does not reflect most real
for up to a lifetime. acoustic and LTM is life memory activities where what we are trying to remember is meaningful. So we might say the
mainly semantic. study lacks external validity.
Coding: CODING CAPACITY
The format in which Once information gets Jacobs used the digit span technique and found the average digit span was
information is stored in into the memory 9.3 items for digits and 7.3 items for letters. Jacobs suggested that this is
the various memory system, it is stored in because there are only 10 digits but 26 letters. Miller reviewed this research
stores. different formats and came up with the 7+/-2 theory with capacity of STM. They found 5 words
Capacity: depending on the is as easy to remember as letters (chunking).
The amount of memory store. The
information that can be process of converting DURATION
held in a memory store. information from one LTM: Bahrick et al asked people of various ages to put names to faces in their
Duration: form to another is high school yearbook. 48 years on people were 70% accurate when they had a
The length of time called coding. picture as a cue (better recall when a cue was given). It shows how memories
information can be held stored in the long term memory has no known capacity.
in memory. Baddeley got
participants to STM: Peterson and Peterson showed 24 students a nonsense trigram followed
remember a list of by a three digit number. They had to count back from this name in 3s or 4s (to
Short term memory: words, read out one prevent rehearsal) and were then asked to recall the trigram. Participants
The limited capacity per second and then remembered about 90% when there was a 3 second gap and 8% with a 18
memory store. Coding recall them in order. second gap.
is mainly acoustic, List A had
acoustically similar Evaluation:
capacity is between 5 1. Artificial stimuli - one limitation of Baddeley’s study is that it used artificial stimuli rather than
and 9 items and words. List B had meaningful material. The word lists had no personal meaning to the participants. That means we
duration is between 18 acoustically dissimilar should be cautious when generalising the results to different kinds of memory tasks.
and 30 seconds. words. List C had 2. Lacking validity - one limitation of Jacob’s study is that it was conducted a long time ago. Early
semantically similar research in psychology often lacked adequate control e.g. some participants may have been
Long term memory: distracted whilst they were being tested so didn’t perform as well as they might have. This means
The permanent words. Group D had there were confounding variables that were not controlled.
memory store. Coding semantically 3. One limitation of Miller’s research is that he may have oversized the capacity of the STM. Cowan
is mainly semantic, it dissimilar words. The concluded the capacity of STM was only about 4 chances, suggesting the lower estimate of Millers
results showed that estimate (5 items) is more accurate.
has unlimited capacity 4. Meaningless stimuli in STM study - a limitation of Peterson and Peterson’s study is that the
and can store memory STM is mainly stimulus material was artificial. Trying to memorise consonant syllables does not reflect most real
for up to a lifetime. acoustic and LTM is life memory activities where what we are trying to remember is meaningful. So we might say the
mainly semantic. study lacks external validity.
