Key Psychologist - coding, capacity and duration

Baddeley

• coding

• aim - wanted to see if information is coded acoustically or semantically

• procedure:

  • gave 4 different groups a list of words

  • acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar

  • tested STM - did a memory test right after

  • tested LTM - did a memory test after 20 minutes

• findings:

  • STM is coded acoustically

  • LTM is coded semantically

Jacobs

• capacity - how much information can be held in the STM

• procedure

  • digit span test

  • researcher would read out a list of digits and letters out loud

  • the participant would have to recall the digits/letters in order

  • the researcher would add another number/letter until the participant can’t remember anymore

• findings

  • participants could recall more digits than letters

  • digits recalled - 7

  • letters recalled - 5

Miller

• capacity - how much information can be held in the STM

• procedure:

  • reviewed Jacobs study

  • observed everyday practice

    • noticed that everything comes in 7 e.g. 7 days a week, 7 deadly sins

• findings:

  • developed the idea of chunking - grouping items together to make it easier to remember

    • helps hold information

  • thought that the capacity of STM was about 7±2 items

Peterson and Peterson

• duration of STM

• procedure:

  • 24 students - each student did 8 trials

  • were given a consonant syllable to remember

  • also given a 3-digit number to count backwards from

  • after a certain amount of time they were asked to stop counting

  • they then had to remember their consonant syllable

• findings:

  • durations of STM was around 18 seconds

Bahrick

• duration of LTM

• procedure:

  • 392 Americans

  • used high school yearbooks to test memory

  • tested 2 types of memory

    • photo recognition

    • naming people

• findings:

  • 15 years of recognition

    • photo recognition - 90%

    • naming people - 60%

  • after 48 years

    • photo recognition - 70%

    • naming people - 30%