Capacity

Question 1

Who studied capacity of the STM?

Answer 1

Jacobs (1887)

Miller (1956)

Question 2

How did Jacobs study capacity in STM?

Answer 2

Measured digit span: had to remember increasing numbers of digits until order cannot be recalled correctly

Question 3

What did Jacobs find?

Answer 3

Ppts could recall an average of:

9. 3 numbers
10. 3 letters

Question 4

How did Miller study capacity in STM?

Answer 4

Through observations in everyday practise.

Question 5

What did Miller find?

Answer 5

Things come in 7s! - days of the week, music scale etc.
so… capacity of STM is about 7 items (+/- 2).
Miller noticed chunking could also improve this

Question 6

Who studied coding?

Answer 6

Baddeley - STM and LTM

Question 7

How did Baddeley study coding?

Answer 7

4 conditions of ppts:

• acoustically similar words
• acoustically dissimilar words
• semantically similar words
• semantically dissimilar words

Question 8

What did Baddeley find?

Answer 8

Immediate recall WORSE with acoustically similar words so STM is acoustic
Recall after 20 mins worse with semantically similar words so LTM coded semantically

Question 9

Who studied duration of STM?

Answer 9

Peterson and Peterson

Question 10

How did Peterson and Peterson study STM?

Answer 10

Gave ppts a consonant syllable (eg:YCG). Then had to count backwards from a 3 digit number, for 3,6,9,12,15 or 18 seconds

Question 11

What did Peterson and Peterson find?

Answer 11

High recall after 3 seconds.

by after 18 seconds fell to 3% - suggesting duration of STM is 18-30 seconds.

Question 12

Who studied duration of LTM?

Answer 12

Bahrick

Question 13

How did Bahrick study duration?

Answer 13

392 American ppts aged 17 - 74

1) Given a recognition test of photos from high school yearbook
2) Free recall test of people from grad class

Question 14

What did Bahrick find?

Answer 14

After 48 years of graduation photo recognition was 70% accurate. Free recall = worse
so showing that LTM capacity is potentially infinite