Coding, capacity and duration of Memory
AO1 - knowledge AO3 - evaluation
Research on Coding Strength - Separate memory stores
This study identifies a clear difference between memory stores. His findings have stood the test of time and
The process of converting information between different forms is called coding. greatly contributed to an understanding of the memory system, in particular the multi-store model.
Baddeley gave different lists of words to four groups of participants, differing by
acoustically similar, acoustically dissimilar, semantically similar and semantically
dissimilar.
Weakness - Artificial stimuli
When asked to recall from short term memory, Ps tended to do worse with Word lists had no meaning to participants, and therefore do not tell us much about everyday life, where people
acoustically similar words. When asked to recall from long term memory, they did may use semantic coding even for STM tasks. Limited Application.
worse with semantically similar words. Information is coded acoustically in
STM and semantically in LTM.
Strength - A valid study
Research on Capacity Jacobs’ study has been replicated. Early research like his often lacked adequate controls however, his findings
Jacobs tested digit span by reading out four digits and asking a participant to have been confirmed by more recent studies. Valid test of digit span in STM.
recall these in the correct order. If done so correctly, five digits are read out, and
will increase until the digits cannot be correctly recalled. The mean digit span
was 9.3 and 7.3 for letters. Weakness - Not so many chunks
Miller made observations that most things were chunked into 7, and therefore Cowan reviewed other research and found that capacity is only around 4 chunks and so Miller may have
concluded that the STM capacity was about 7 items. He also found that people overestimated in his conclusion of seven items.
can recall 5 letters just as easily as 5 words, by chunking digits and letters.
Research on Duration Weakness - Meaningless stimuli in STM study
Peterson tested duration of STM. 24 students were given a consonant syllable Recalling consonant syllables does not reflect most everyday memory activities where what we are trying to
remember is more meaningful. The study therefore lacks external validity
and a three digit number to count down from to prevent rehearsal over varying
periods of time. After 3 seconds, recollection was 80%. After 18 seconds this
dropped to 3%. STM duration is 18 seconds.
Bahrick tested duration of LTM. 392 participants were tested on high school Strength - High external validity
Researchers investigated meaningful memories. When studies on LTM were conducted with meaningless
yearbook photos. After 15 years, photo recognition was 90% and after 48 this pictures, recall rates were lower. Bahrick’s studies reflect a more accurate estimate of LTM duration.
declined only to 70%. LTM duration can last up to a lifetime.
, The Multi-Store Model
AO2 - knowledge AO3 - evaluation
retrieval Strength - Research evidence
LTM and STM are qualitatively different. Baddeley found that we mix up words that are similar
sounding in our STM, acoustically, and we mix up words that have similar meaning in our LTM,
semantically. Further studies on capacity, coding and duration show how the LTM and STM are
independent, supporting the MSM.
stimulus attention rehearsal
SENSORY
STM LTM
MEMORY
Weakness - MSM only has one type of STM
There is research evidence for more than one type of STM, i.e the Working Memory Model.
Furthermore, KF, a patient with amnesia, struggled to recall words when read to him, auditory,
but recalled much better when he read words to himself, visually. Therefore, there is more than
one store.
- decay - displacement - interference
- decay - decay
- retrieval failure
Weakness - Real life application
Most studies that support the MSM are based off of insignificant materials, for example lists of
words or consonant syllables, when in reality, the memory is used to recall much more
important things like names, places and facts.
Weakness - MSM only has one type of LTM
The diagram is oversimplified as later studies show different stores within the LTM, including
the episodic, semantic and procedural stores. Each work individually.
AO1 - knowledge AO3 - evaluation
Research on Coding Strength - Separate memory stores
This study identifies a clear difference between memory stores. His findings have stood the test of time and
The process of converting information between different forms is called coding. greatly contributed to an understanding of the memory system, in particular the multi-store model.
Baddeley gave different lists of words to four groups of participants, differing by
acoustically similar, acoustically dissimilar, semantically similar and semantically
dissimilar.
Weakness - Artificial stimuli
When asked to recall from short term memory, Ps tended to do worse with Word lists had no meaning to participants, and therefore do not tell us much about everyday life, where people
acoustically similar words. When asked to recall from long term memory, they did may use semantic coding even for STM tasks. Limited Application.
worse with semantically similar words. Information is coded acoustically in
STM and semantically in LTM.
Strength - A valid study
Research on Capacity Jacobs’ study has been replicated. Early research like his often lacked adequate controls however, his findings
Jacobs tested digit span by reading out four digits and asking a participant to have been confirmed by more recent studies. Valid test of digit span in STM.
recall these in the correct order. If done so correctly, five digits are read out, and
will increase until the digits cannot be correctly recalled. The mean digit span
was 9.3 and 7.3 for letters. Weakness - Not so many chunks
Miller made observations that most things were chunked into 7, and therefore Cowan reviewed other research and found that capacity is only around 4 chunks and so Miller may have
concluded that the STM capacity was about 7 items. He also found that people overestimated in his conclusion of seven items.
can recall 5 letters just as easily as 5 words, by chunking digits and letters.
Research on Duration Weakness - Meaningless stimuli in STM study
Peterson tested duration of STM. 24 students were given a consonant syllable Recalling consonant syllables does not reflect most everyday memory activities where what we are trying to
remember is more meaningful. The study therefore lacks external validity
and a three digit number to count down from to prevent rehearsal over varying
periods of time. After 3 seconds, recollection was 80%. After 18 seconds this
dropped to 3%. STM duration is 18 seconds.
Bahrick tested duration of LTM. 392 participants were tested on high school Strength - High external validity
Researchers investigated meaningful memories. When studies on LTM were conducted with meaningless
yearbook photos. After 15 years, photo recognition was 90% and after 48 this pictures, recall rates were lower. Bahrick’s studies reflect a more accurate estimate of LTM duration.
declined only to 70%. LTM duration can last up to a lifetime.
, The Multi-Store Model
AO2 - knowledge AO3 - evaluation
retrieval Strength - Research evidence
LTM and STM are qualitatively different. Baddeley found that we mix up words that are similar
sounding in our STM, acoustically, and we mix up words that have similar meaning in our LTM,
semantically. Further studies on capacity, coding and duration show how the LTM and STM are
independent, supporting the MSM.
stimulus attention rehearsal
SENSORY
STM LTM
MEMORY
Weakness - MSM only has one type of STM
There is research evidence for more than one type of STM, i.e the Working Memory Model.
Furthermore, KF, a patient with amnesia, struggled to recall words when read to him, auditory,
but recalled much better when he read words to himself, visually. Therefore, there is more than
one store.
- decay - displacement - interference
- decay - decay
- retrieval failure
Weakness - Real life application
Most studies that support the MSM are based off of insignificant materials, for example lists of
words or consonant syllables, when in reality, the memory is used to recall much more
important things like names, places and facts.
Weakness - MSM only has one type of LTM
The diagram is oversimplified as later studies show different stores within the LTM, including
the episodic, semantic and procedural stores. Each work individually.
