STM: Capacity - Joseph Jacobs 1887

Question 1

How can the capacity of STM be assessed?

Answer 1

Using a digit span.

Question 2

Who used the digit span in one of the earliest studies in psychology?

Answer 2

Joseph Jacobs (1887)

Question 3

What did Joseph Jacobs fin that the average span for digits was?

Answer 3

9.3 digits and 7.3 for letters.

Question 4

Did Joseph Jacobs (1887) find that it was easier to recall letters or digits?

Answer 4

Digits.

Question 5

What was Joseph Jacobs’ (1887) suggestion of the reason that it was easier to recall digits?

Answer 5

There are only 9 digits whereas there are 26 letters.

Question 6

Who then claimed the number?

Answer 6

George Miller.

Question 7

When did Miller call the number the magic number?

Answer 7

1956.

Question 8

What did Miller conclude?

Answer 8

That the span of immediate memory is about 7 items, sometimes a bit more, sometimes a bit less.

Question 9

What did Miller also find?

Answer 9

That people can recall five words as well as they can recall five letters - we chunk things together and can then remember more.

Question 10

What is Miller’s magic number (1956)?

Answer 10

7±2