research on capacity of STM

Question 1

who did research on capacity of STM

Answer 1

joseph Jacobs in 1887 measured the capacity of the STM using digit span

the mean digit span across all participants was 9.3

Question 2

evaluate the research on the capacity of stm

Answer 2

+ study has been replicated
+ replication suggests Jacob’s study is a valid test of digit span in STM
- some older studies lacked proper controls (so there was likely confounding variables)

Question 3

what was george millers research on the capacity of stm

Answer 3

George miller 1956 observed that many items in life come in groups of 7

believed capacity of STM was 7+- 2

Question 4

evaluate George millers research on the capacity of STM

Answer 4

• may have overestimated STM capacity
• cowan (2001) reviewed other research
  concluded that STM capacity is 4+-1
• millers lower estimate of 5 may be closer to reality