Matched pairs

• • partic takes part in 1 condition
  • matched pairs similar to independent measures
  • each group randomly assigned to one level of the IV
  • partic matched by key characteristics (e.g. age, gender, etc.) that may affect outcomes
  • each partic allocated at random to A or B
  • one group gets coffee, one doesn't (IV)
  • memory measured by number of words recalled (DV)
• Advantages


  • partic variables: kept more constant between conditions
  • no order effects: partic only takes part in one condition
  • demand characteristics: decreased problem as the partic is only in one condition
• Disadvantages


  • partic variable never perfectly matched
  • matching partic is very time consuming & difficult
  • more partic required ( due to needing to be matched & take part in only one level) = lower economical validity than independent + repeated measures
• Ways to deal with disadvantages

  • restrict the number of variables to match partic on. conduct a pilot study to consider key variables that might be important when matching