Experimental Design

• Experimental design


  Refers to the way in which participants are arranged in experimental conditions
• Independent groups design


  Two separate groups of participants experiencing two different conditions
• Evaluations of independent groups

  WEAKNESSES

  -participant variable can confound results

  -Twice as many participants are needed

  STRENGTHS

  -No order effects

  -Reduces demand characteristics
• repeated measures design


  All participants take part in all conditions of the experiment
• Evaluation of repeated measures

  WEAKNESSES

  -order effects

  -demand characteristic

  STRENGTHS

  -Participant variables can be controlled

  -Fewer participants are needed
• Matched pairs


  Participants would be paired up based on a trait relevant to the study and then split into different conditions
• Evaluation of matched pairs

  WEAKNESSES

  -Time consuming and expensive

  STRENGTHS

  -No order effects

  -Reduces demand characteristics

  -Impact of participant variables are reduced