Peterson and Peterson Short-Term Memory Duration

• Aim

  To investigate how long short-term memory lasts without rehearsal.
• Procedure

  Participants were shown trigrams and asked to recall them after counting backwards in threes (to prevent rehearsal).
• Findings

  Short-term memory lasted about 18 seconds without rehearsal.
• Strengths

  • Controlled experiment: Reliable, repeatable results.
  • Scientific method: Objective measurement of memory duration.
• Weaknesses

  • Artificial task: Remembering random letters is not like real-life memory use.
  • Limited external validity: Results may not apply to all types of memory.