Peterson and peterson

• Aim:

  To investigate of short term memory, test hypothesis that information that is not rehearsed is lost quickly from STM
• Procedure:

  • lab experiment
  • 24 participants psychology students
  • Trigrams were presented one at a time had to be recalled after intervals of 3,6,9, 12,18 seconds for each trial
  • After hearing trigrams participants acked to count backwards in threes and fours  to prevent maintenance 
  • 6 trials
• Independent variable:

  Duration of distracted task
• Dependant variable 

  % of correct recall of trigram 
• Results 

  • longer student had to count background less well able to recall trigram 
  • After 3 seconds 80% of triagrams were recalled correctly
  • After 6 seconds fell to 50%
  • After 18 seconds less than 10%