Coding, Capacity and Duration

• What is the definition of memory?

  Process to retain past events
• What are the key terms related to memory?

  • **Coding**: Format of stored information
  • **Capacity**: Amount of information storable
  • **Duration**: Time information retained
• What is the capacity of short-term memory (STM)?

  1. 9 items
• What type of coding is used in short-term memory (STM)?

  Acoustic
• What is the duration of short-term memory (STM)?

  18-30 seconds
• What is the nature of long-term memory (LTM)?

  Permanent storage
• What type of coding is used in long-term memory (LTM)?

  Semantic
• What is the capacity of long-term memory (LTM)?

  Unlimited / very large
• What is the duration of long-term memory (LTM)?

  Up to a lifetime
• What is the definition of encoding in memory?

  Changing information for storage
• What type of coding is used in STM and LTM?

  STM uses acoustic coding, LTM uses semantic coding
• What was the focus of Baddeley's (1966) research on coding?

  Testing word lists with different similarities
• What were the findings of Baddeley's (1966) research on STM?

  STM was worst for acoustically similar words
• What were the findings of Baddeley's (1966) research on LTM?

  LTM was worst for semantically similar words
• What is a strength of Baddeley's research on coding?

  • Control of extraneous variables
  • High internal validity
• What is a weakness of LTM testing in Baddeley's research?

  • Short time gap in tests
  • Real-world recall typically has longer gaps
• What is the definition of capacity in memory?

  Information storage limit in STM and LTM
• What were the findings of Jacobs' (1887) research on STM?

  Average digit span = 9.3
• What was the focus of Joseph Jacobs' (1887) research?

  Measured STM digit span
• What did Miller (1956) conclude about STM capacity?

  STM capacity is approximately 7 items (+/-2)
• How does chunking affect STM capacity?

  Chunking increases capacity
• What was Wagenaar's (1986) research focus on LTM capacity?

  Diary study of events over six years
• What were the findings of Wagenaar's (1986) research on LTM capacity?

  Very high LTM capacity
• What is a strength of Jacobs' research on capacity?

  • Age effects on STM capacity
  • Capacity increases with age
• What is a weakness of Wagenaar's case study method?

  • Lacks population validity
  • Subjective bias in results
• What is the definition of duration in memory?

  Time info held in STM and LTM
• What was the focus of Sperling's (1960) research on sensory store duration?

  Brief exposure of number grid
• What was the focus of Peterson & Peterson's (1959) research on STM duration?

  Trigram recall with backward counting
• What was the focus of Bahrick et al.'s (1975) research on LTM duration?

  Yearbook photo recognition
• What were the findings of Sperling's (1960) research on sensory store duration?

  Limited retention, high decay rate
• What were the findings of Peterson & Peterson's (1959) research on STM duration?

  Duration limited without rehearsal
• What were the findings of Bahrick et al.'s (1975) research on LTM duration?

  90% accuracy after 15 years, 30% after 48 years
• What is a strength of Bahrick's study on duration?

  • High external validity
  • High generalisability to real life
• What is a weakness of Peterson & Peterson’s study on duration?

  • Artificial stimuli used
  • Low external validity, unrepresentative of real-life memory tasks