coding, capacity & duration of memory

Question 1

coding for STM

Answer 1

acoustic (sounds) - mainly

Question 2

coding for LTM

Answer 2

semantic (meaning) - mainly

Question 3

capacity of STM

Answer 3

5 to 9

Question 4

duration of STM

Answer 4

approx. 18 seconds

Question 5

capacity of LTM

Answer 5

unlimited

Question 6

duration of LTM

Answer 6

whole lifetime (limitless)

Question 7

who conducted the research on coding

Answer 7

Baddeley - 1966

Question 8

describe the research on coding by baddeley 1966

Answer 8

• different lists of words to 4 groups:
  
  • 1 (acoustically similar)
  • 2 (acoustically dissimilar)
  • 3 (semantically similar)
  • 4 (semantically dissimilar)
• participants shown original words & asked to recall in correct order
  = done immediately (STM) = worse in acoustically similar
  = done after time interval (20 min) = worse in semantically similar

Question 9

what does Baddeley’s (1966) research suggest

Answer 9

STM is coded acoustically
LTM is coded semantically

Question 10

which 2 researchers conducted the research on capacity

Answer 10

Jacobs (1887)
Miller (1956)

Question 11

describe Jacobs (1887) research on capacity

Answer 11

• measured digit span
  eg. reads out 4 digits & participant recalls these out loud in correct order - if these are correct, the researcher reads out 5 digits etc.

Question 12

Jacobs (1887) results

Answer 12

mean span for digits was 9.3
mean span for letters was 7.3

Question 13

describe Millers (1956) research on capacity

Answer 13

• span of memory and chunking
• made observations of everyday practice
  eg. he noted things that come in sevens
• thought that span of STM is 7 items +- 2
• noted people remember 5 words as easily as 5 letters - do so by chunking

Question 14

who researched the duration of the STM

Answer 14

Peterson & Peterson (1959)

Question 15

describe the research of duration of the STM

Answer 15

• tested 24 students in 8 trials
• each trial: student given consonant syllable to remember & 3-digit number
• student counted back from this number until told to stop (stop mental rehearsal)
• each trial: told to stop after varying amounts of time eg. 3-18 secs (up in 3s)

Question 16

results of Peterson & Peterson (1959) study

Answer 16

• after 3 secs = avg. recall at 80%
• after 18 secs = avg. recall at 3%

Question 17

who researched the duration of LTM

Answer 17

Bahrick et al. (1975)

Question 18

describe the research on the duration of LTM

Answer 18

• 392 american participants aged 17-74
  used yearbook in 2 groups:
  1) photo-recognition of 50 photos - some from yearbooks
  2) free recall test of all names in graduating class

Question 19

results of research on duration of LTM

Answer 19

• after 15 years of graduation = 90% accurate in photo recognition & 60% in free recall
• after 48 years = 70% for photo recognition & 30% for free recall

Question 20

evaluation of research on coding - AO3

Answer 20

+)
P: baddeleys study identified clear difference between 2 memory stores
E: coding for STM is acoustic & LTM is semantic
T: important understanding that led to the multi store model

-)
P: baddeleys study used artificial stimuli
E: word lists had no personal meaning to participants - findings may not tell us about coding in everyday memory tasks (people may use semantic coding for meaningful material in STM)
T: findings have limited application

Question 21

evaluation of research on capacity - AO3

Answer 21

+)
P: jacobs study has been replicated
E: an old study and early research that may have lacked adequate control eg. some digit spans may be underestimated as individual was distracted during (confounding variable) but the results have been confirmed by other studies (eg. Bopp and Verhaeghen 2005)
T: study is a valid test of digit span in STM

-)
P: millers research may have overestimated STM capacity
E: Nelson Cowan (2001) reviewed other research & concluded capacity of STM is only 4+/-1 chunks
T: lower end of Millers estimate is more appropriate than 7

Question 22

evaluation of research on duration - AO3

Answer 22

+)
P: bahrick et. al’s study had high external validity
E: investigated meaningful memories (peoples names/faces) & when testing meaningless material recall rates were lower (eg. Shepard 1967)
T: results show more ‘real’ estimate of duration of LTM

-)
P: peterson & peterson’s stimulus material was artificial
E: recalling constant syllables doesn’t reflect most everyday memory activities
T: lacks external validity