capacity

Question 1

Digit span study

Answer 1

• Jacobs 1887
• mean of STM is 9.3 digits or 7.3 letters

Question 2

Span of memory + chunking

Answer 2

• miller 1956
• made observations of everyday practices e.g. 7 days of week, 7 deadly sins, 7 music notes
• span of STM is 7 ± 2
• CHUNKING: group letters/digits into chunks makes it easier to recall e.g. can recall 5 works as easily as 5 letters

Question 3

A03 strength

Answer 3

• controlled lab experiment
• Jacobs removed the letter W and number 7 as they were 2 syllables so would affect results
• replicable
• reliable
• CA: low external validity, in real life might be distractions that make recall less

Question 4

A03 weakness (date)

Answer 4

• Jacobs research outdated, nearly 150 years ago
• test standards may have been different to now, lack control
• extraneous variables e.g. age, IQ
• lack internal validity

Question 5

A03 weakness (evidence)

Answer 5

• millers study has contradictory research
• Cowan (2001) said capacity of STM 4 chunks
• lacks inter-observer reliability
• less validity