Coding, Capacity and Duration

• Who investigated coding in the long and short term memory?

  Baddeley.
• What was the aim of Baddeley's research into the coding of long and short term memory?

  To investigate how information is coded in both short term and long term memory.
• What was the procedure of Baddeley's research into the coding of long and short term memory?

  A laboratory experiment which consisted of four conditions for the independent variable:

  • Acoustically similar
  • Acoustically dissimilar
  • Semantically similar
  • Semantically dissimilar

  Participants were shown words and asked to recall them in the correct order.
• What were the findings of Baddeley's research into the coding of long and short term memory?

  When recalled immediately, testing short term memory, participants performed worse with acoustically similar words.

  When recalled after 20 minutes, testing long term memory, participants performed worse in semantically similar words.
• What was the conclusion of participants Baddeley's research into the coding of long and short term memory?


  The findings suggest that information is coded acoustically in the short term memory and semantically in the long term memory
• Who investigated capacity of the short term memory?

  Jacobs
• What was the aim of Jackob's research into the capacity of short term memory?

  To investigate the capacity of short term memory.
• What was the procedure of Jackob's research into the capacity of short term memory?

  Participants were given a sequence of digits and asked to recall them in the correct order out loud. E.g. 4, 1, 6, 2

  If done correctly they will move onto the next sequence whereby another digit is added. E.g. 4, 1, 6, 2, 9

  This process is repeated until they cannot recall the order correctly
• What were the findings of Jackob's research into the capacity of short term memory?

  The mean span for digits was: 9.3

  The mean span for letters was: 7.3
• What was the conclusion of Jackob's research into the capacity of short term memory?

  The findings suggest that the average capacity in short term memory is between 5-9.
• Miller suggested that people can recall five words as easily as they can recall five letters, this is done by a process called chunking.
• Who investigated duration into short term memory?

  Peterson and Peterson
• What was the aim of Peterson and Peterson's research into the duration of short term memory?

  To investigate the duration of short term memory.
• What was the procedure of Peterson and Peterson's research into the duration of short term memory?

  • 24 psychology student participants completed 8 trials.
  • Each trial, participants were given a consonant trigram to remember and a 3 digit number to count backwards from the prevent rehearsal.
  • The distraction task was necessary to form a control to stop participants rehearsing the numbers which could have acted as a confounding variable.
  • On each trial they were told to stop after a different amount of time. E.g. 3, 6, 9, 12, 15 and 18 seconds.
• What were the findings of Peterson and Peterson's research into the duration of short term memory?

  80% of participants recalled correctly after 3 seconds, 3% recalled correctly after 18 seconds.

  It was concluded that the duration of the short term memory was approximately 18 seconds without any verbal rehearsal.
• What was the conclusion of Peterson and Peterson's research into the duration of short term memory?

  The findings suggest that the duration of short term memory is somewhere between 18-30 seconds.
• Who investigated the duration of short term memory?

  Bahrick
• What was the procedure of Bahrick's research into the duration of long term memory?

  • 392 American participants aged between 17 and 74. Highschool year book were obtained either from the participants directly or the school.
  • Highschool year book were obtained either from the participants directly or the school.

  Recall was tested in 2 ways:

  1. Photo recognition - Participants were shown 50 high school photos and were asked to match a group of names to the photographs.
  2. Free recall - Participants were asked to recall the names of students in their graduating class.
• What were the findings of Bahrick's research into the duration of long term memory?

  Condition 1, photo recognition:

  • Recall within 15 years of graduation = 90% accuracy.
  • Recall after 48 years of graduation = 70% accuracy.

  Condition 2, free recall:

  • Recall within 15 years of graduation = 60% accuracy.
  • Recall within 48 years of graduation = 30% accuracy.
• What was the conclusion of Bahrick's research into the duration of long term memory?


  The findings suggest that recognition is better than recall, so there may be a huge store of information but not always an easy way to access it.