research into capacity of memory

Question 1

capacity

Answer 1

capacity refers to how much information can be held in memory at any one time

Question 2

two researchers into capacity of STM

Answer 2

Joseph Jacobs (1887)

George Miller (1956)

Question 3

Joseph Jacob’s

Answer 3

Used a digit span test to assess capacity of STM
-590,4861,73094 etc until they couldn’t do anymore

digits:9.3 letters:7.3
more letters to remember

Question 4

george miller (1956)

Answer 4

Found that people could roughly absorb 7 new pieces of information in STM at a time.
• Magical number 7+/-2
This was also the case for words.
→ Chunking

Question 5

LTM

Answer 5

unlimited capacity

Question 6

strength-replication of Jacobs study

Answer 6

Although older studies often lacked adequate controls.
For example, some participants’ digit spans might have been underestimated because they were distracted during testing (confounding variable).
Jacob’s findings have been confirmed by other, better controlled studies since.
This suggests that Jacob’s study is a valid test of digit span in STM.

Question 7

limitation-too many chunks

Answer 7

Miller may have overestimated STM capacity.
-Cowan reviewed other research → capacity of STM is only about 4 (+/- 1) chunks.
• Vogel et al conducted research on the capacity of
STM for visual information → 4 chunks is the limit.
• This suggests that the lower end of Miller’s estimate (five items) is more appropriate than seven items.