Experimental Designs

• Repeated Measures


  Participants complete both conditions of the experiment
• Strength of Repeated Measures


  Eliminates participant variables
• Limitations of Repeated Measures 


  High risk of order effects such as fatigue, practice and demand characteristics that will show in condition B
• Independent Measures 


  Participants take part in one condition only

  Comparisons are made between two separate groups
• Strengths of Independent Measures 


  No order effects

  Lower risk of Demand Characteristics
• Limitation of Independent Measures


  Participant variables / individual differences may explain behavioural change
• Matched Pairs Design

  Participant are matched on important variables in a study

  One person in a pair completes condition A and the other completes condition B

  Not randomly assigned partners but assigned due to similar traits
• Strength of Matched Pairs design


  Reduced risk of participant variables
• Limitation of Matched Pairs design


  Not possible to get a completely perfect match