experimental methods

• lab experiments


  • researcher has high levels of control
  • uses a standardised procedure to ensure reliability
  • variables kept the same
• strengths of lab experiments


  • cause and effect relationship is difficult to establish
  • replicible = high reliability
  • high internal validity
• limitations of lab experiments


  • demand characteristics
  • lacks ecological validity
  • lacks mundane realism
• quasi experiments


  compares between two variables that cannot be changed
• natural experiments


  • does not manipulate the IV
  • uses a naturally occuring phemomena
  • researcher has less control
  • quantative data
• strengths of natural experiments


  • allows research in areas that controlled research would be unethical
  • high external validity
• limitations of natural experiments


  • difficult to establish cause and effect
  • lack of reliability
• field experiments


  • takes place in a natural setting
  • researcher has less control over variables
  • quantative data
• strengths of field experiments


  • higher ecological validity
  • less likely to show demand characteristics
  • higher levels of mundane realism
• limitations of field experiments


  • harder to randomly assign participants
  • harder to control extraneous variables