Capacity AO1 + AO3

Question 1

what is capacity?

Answer 1

the amount of information that can be held in memory stores

Question 2

describe the digit span

Answer 2

• joseph jacobs 1887 reads out 4 digits and the ppts recall these out loud in the correct order
• if the order is correct the researcher reads out further digits until the ppts cannot recall the order correctly
• mean span for digits across all ppts was 9.3 items
• mean span for letters 7.3

Question 3

A03 what is the strength of the digit span?

Answer 3

• jacobs study has been replicated
• study is old and lacked adequate controls
• e.g some ppts digit span might have been underestimated because they were distracted = confounding variables
• findings have been confirmed by other better-controlled studies since Bopp and Varhaeghen
• suggests that jacobs study is a valid test of digit span in the stm

Question 4

George Miller 1956 procedure and findings

Answer 4

• miller made observations of everyday practice
• he noted that things come in 7, days of the week, musical notes etc
• span (capacity) of stm is about 7+-2 items
• people can recall 5 words as easily as 5 letters
• do this by chunking- grouping sets of digits or letters into units or chunks

Question 5

AO3 what is a limitation of George millers study?

Answer 5

• nelson cowan 2001 reviewed other research and conclude that the capacity of STM is only about 4+-1 chunks
• suggests that the lower end of millers estimate is more appropriate than 5 items