Coding, capacity and duration of memory

Research for coding

Baddeley used a word recall of 4 groups (either acoustically similar or dissimilar or semantically similar or dissimilar) to find the STM is coded acoustically and the LTM is coded semantically. Tasked to recall words in the correct order.

Research for capacity

Jacobs told participants to recall some digits which had been read out to them and found the mean digit span was 9.3 and mean letter span recall was 7.3

Research for capacity (chunking)

Miller found chunking could be used to recall 5 words as easy as 5 letters. Chunking is grouping things together. He found the capacity of the STM was 7 + - 2

Research for duration in the STM

Peterson and Peterson used a consonant recall to establish the duration of the STM was 18 secs unless we rehearse information.

Research for duration of the LTM

Bahrick used a school year book and name and photo recall to find that the LTM duration might last a life time after finding participants could still recall after 48 years. Face recognition was more accurate then free recall.

Evaluation strength for research on coding

Clear difference between the two memory stores. STM acoustic and LTM semantic. Increased our understanding of memory which led to the multi store model of memory.

Evaluation limitation of research on coding

Artificial stimuli which isn’t meaningful so doesn’t tell us about coding in different kids of memory tasks. This means findings have limited application so less use in understanding the memory systems.

Evaluation limitation of research into duration for Jacob’s

Findings may have been a result of confounding variables for example some participants may have been distracted which led to there digit spans being underestimated. This means Jacob’s study may lack internal validity as findings may not have measured what Jacob’s intended to as it isn’t certain the Iv led to the Dv.

Evaluation limitations for research into capacity , miller.

He may have overestimated the STM capacity. Cowan found capacity of the stm is only 4 plus or minus 1 which suggests millers lower estimate of 5 may be more appropriate than 7, reduces the use and validity of millers findings which decreases our understanding of capacity of the stm and memory stores in general.

Evaluation limitation of Petersons research into the duration of the stm.

Stimuli was meaningless and artificial meaning that behaviour may be artificial. Consonant syllables don’t represent everyday memory activities meaning the story lacks external validity and is not useful in understanding the duration of the stm in every day scenarios.

Evaluation strength for research into the duration of the LTM

Bahricks study has high external validity because meaningful memories were researched. Shepard found meaningless pictures had a lower recall rate meaning they were harder to remember which increases the validity and use of bahricks study in understanding the LTM and memory in general.