2.1 Coding, Capacity and Duration

Coding
1. Baddeley (1966)
  1. Gave lists of words to 4 groups of participants which were 1. acoustically similar 2. acoustically dissimilar 3. semantically similar 4. semantically dissimilar
  2. STM - acoustically coded
  3. LTM - semantically coded
  4. Evaluation
    1. Strength: Identified a clear difference between the LTM and STM. Led to the multi-store model.
    2. Weakness: Used artificial stimuli rather than meaningful material. Word list had no personal meaning to the participants.
Capacity
1. Jacobs (1887) Digit span
  1. STM- Found that the mean span of digits stored was 9.3 and mean span for letter was 7.3
2. Miller (1956) Span of memory
  1. STM can only 7+/- 2 items
3. Evaluation
  1. Strengths:
    1. Jacobs study can be replicated. His findings have been confirmed by other researchers, meaning it is a valid test of digit span.
  2. Weaknesses:
    1. Miller's research may have overestimated stm capacity. Cowan reviewed other research and found that STM is only 4+/- 1 chunk.
Duration
1. STM
  1. 0-18 seconds
  2. Peterson and Peterson (1959) tested 24 students, each student was given a consonant syllable and a 3 digit number.
2. LTM
  1. Unlimited
  2. Bahrick et al (1975) showed American participants between 17-74 their highschool yearbook. Tested in two ways, photo recognition and recalling names. Those tested within 15 years of graduation were about 90% accurate, after 48 years recall dropped to 70%.
3. Evaluation
  1. Strengths:
    1. High external validity. Bahrick's study includes meaningful memories so there is a real estimate to the duration of LTM.
  2. Weaknesses:
    1. Meaningless stimuli in STM study. Peterson and Peterson study used consonants which do not reflect everyday memory.

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2.1 Coding, Capacity and Duration

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	Created by Alicja Klak over 1 year ago