AO1 - Capacity

• Who conducted research on capacity in 1887?

  Jacobs
• What task did Jacobs use to measure digital span?

  Participants recalled digits out loud
• What is digital span?

  Number of items recalled correctly
• What was the average digital span found by Jacobs?

  9.3 for digits
• What was the mean span for letters according to Jacobs?

  7.3
• What is Miller's magic number?

  Capacity of short term memory is 7 items
• In what year did Miller suggest the concept of magic numbers?

  1956
• What did Miller observe about recalling words versus letters?

  People recall five words as well as five letters
• What is chunking in memory recall?

  Grouping items into units to aid recall
• What are the key findings of Jacobs' research on capacity?

  • Average digital span: 9.3 for digits
  • Mean span for letters: 7.3
• What are the key concepts introduced by Miller regarding short term memory?

  • Magic number: 7 items (+/-2)
  • Chunking: grouping items to enhance recall