coding, capacity & duration

Question 1

Outline Alan Baddeley’s research on coding

Answer 1

• Gave different list of words to four groups of ppts to remember
• group1; acoustically similar
• group2; acoustically dissimilar
• group3; semantically similar
• group4; semantically dissimilar
• Ppts were shown original list of words, asked to recall them in the correct order
• When they had to recall immediately after hearing it they tended to do worse with acoustically similar words
• The opposite was true for LTM recall, had to recall 20 minutes after, did worse with semantically similar words.
• This suggesting info is coded semantically in LTM.

Question 2

Outline Jacobs reserach on capacity

Answer 2

• developed a technique to measure digit span
• eg, gives ppts 4 digits, ppts is then asked to recall these in correct order
• if correct the researcher gives more digits until ppts fail to recall correct order
• Jacobs found the mean digit span for digits was 9.3
• the mean span for letters was 7.3

Question 3

Outline Millers observation

Answer 3

• noted things come in sevens
• suggesting the capacity for STM is 7 items
• he also noted that ppl can recall 5 letters and words through chunking

Question 4

Outline Peterson + Petersons research on the duration of STM

Answer 4

• tested 24 undergrad students
• each student took part in 8 trails
• on each trial the students were given a consonant syllable
• they had to also count down from a 3 digit number to prevent maintanance rehearsal
• they were then told to stop after a certain amount of time eg, 3-18 seconds
• findings suggest STM has a short duration unless we repeat the info

Question 5

Outline Bahrick et als research on LTM duration

Answer 5

• studied 392 ppts aged between 17-74
• recall was tested through 1; photo recognision tests of 50 photos
• 2; free recall test of names
• ppts tested within 15 yrs were 90% accurate
• those tested after 15 yrs were 60% accurate
• this dropped to 30% after 48 yrs

Question 6

Name one limitation of Baddeley’s study

Answer 6

• used artificial stimuli rather than meaningful material
• we should be cautious about generalising the findings
• findings have limited application

Question 7

Name one limitation of Jacobs study

Answer 7

• conducted a long time ago
• lacked adequate control
  findings may lack validity
• confounding variables were not controlled

Question 8

Name one limitation of Millers research

Answer 8

• may have overestimated the capacity of STM

- Cowen concluded capacity of STM was only about 4 chunks

Question 9

Name one limitation of Peterson and Peterson’s study

Answer 9

• stimulus material was artificial
• activity does not reflect those of real life
• lacks external validity

Question 10

Name one strength of Bahrick et al.’s research

Answer 10

• higher external validity
• real life memories were studied
• however confounding variables were not controlled