Research STM

Research STM

1. Peterson and Peterson 1959 - duration

   • Investigated STM bu using trigrams
     • After 3s - 80% recalled correctly
       • 18s - 10% recalled correctly
     • When rehearsal is prevented, very little can stay in the STM for no longer than 18s
   • Method
     • Were shown nonsense trigrams and were asked to recall them
       • After 3,6,9,12,15,18 seconds
       • During the pause, they were asked to count backwards in 3s from a given number
         • This was called an interference task
           • Prevented them from repeating answers to themselves
     • Lab Experiment
       • Only 1 type of stimulus was used
         • Could be confusion due to many trigrams seen

2. Miller (1956) reviewed research into the capacity of STM

   • He found that the capacity is 7+- 2 items
     • Suggested that we used 'Chunking' to combine individual letters or numbers into larger more meaningful units