coding, capacity and duration

Question 1

short term memory

Answer 1

limited capacity memory store

mainly acoustic

capacity 7+- 2

duration is 18 seconds

Question 2

long-term memory

Answer 2

the permanent memory store

coding is mainly semantic

unlimited capacity

unlimited duration

Question 3

coding

Answer 3

the format in which information is stored in the various memory stores

Question 4

capacity

Answer 4

the amount of information that can be held in a memory store

Question 5

duration

Answer 5

the length of time information can be held in memory

Question 6

research on coding

Answer 6

Baddeley - list of words to four groups

• acoustically similar and dissimilar
• semantically similar and dissimilar

when task immediately - recalling STM - worst with acoustically - recalled after 20 mins - recalling LTM - semantically

Question 7

coding - separate memory stores

Answer 7

P - strength - identified a clear difference between two memory stores
E - some exceptions to findings
E - idea that stm uses mostly acoustic and ltm mostly semantic consistent
L - important step in understanding of memory led to multi-store model

Question 8

coding - artifical stimuli

Answer 8

P - limitation of Baddeley’s study - artificial stimuli rather than meaningful material
E - word lists have no personal meaning to participants
E - findings not tell us much about coding in different memory tasks, especially in everyday life - if more meaningful then semantic for STM??
L - findings have limited application

Question 9

research on capacity

Answer 9

digit span
- Jacobs
- reads 4 digits and participant recalls out loud
- increase by 1 each time
- mean span was 9.3 digits and 7.3 letters

memory and chunking
- Miller
- observations of everyday practice
- 7=_ 2
- people recall 5 words easily as they can recall 5 letters
- do this by chunking - grouping sets of digits or letters into chunks

Question 10

capacity - valid study

Answer 10

P - strength of Jacobs’ study is has been replicated
E - study is old and early research often lacked adequate controls - some may have been underestimated as distracted eg confounding variables
E - findings confirmed by other studies
L - valid test of digit span in STM

Question 11

capacity - not so many chunks

Answer 11

P - limitation of Miller’s research
E - overestimated STM capacity
E - Cowan - reviewed other research and concluded that capacity of STM is only about 4 chunks
L - lower end of estimate is more appropriate than 7

Question 12

research on duration

Answer 12

STM
- Peterson and Peterson
- consonant syllable to remember and 3-digit number
- counted backwards from number - prevents any mental rehearsal of consonant syllable
- told to stop at varying periods of time - 3,6,9,12
- after 3 seconds - 80% recall
- after 18 - 3% recall

LTM
- Bahrick et al
- High school yearbooks
- photo-recognition test of 50 photos
- 15 years - 90%
- 48 years 70%
- free recall
- 15 - 60%
- 48 - 30%
last up to a lifetime

Question 13

duration - meaningless stimuli

Answer 13

P - limitation of peterson and peterson - stimuli was artificial
E - not completely irrelevant as sometimes do remember meaningless material
E - recalling consonant syllables does not reflect everyday memory
L - lacked external validity

Question 14

duration - high external validity

Answer 14

P - strength of Bahrick et al is high external validity
E - researchers investigated meaningful memories
E - when studies on LTm were conducted with meaningless pictures recall was lower
L - findings reflect a more real estimate of duration