Experimental methods

• 4 types of experiment:

  • Lab
  • Field
  • Quasi
  • Natural
• Lab experiment

  • Controlled environment = extraneous variables controlled = high internal validity
  • Ppts aware of involvement
  • IV directly manipulated by researchers
  • Artificial tasks = low mundane realism = low ecological validity
• Field experiment

  • Not in controlled environment = extraneous variables not controlled = low internal validity
  • IV directly manipulated by researchers
  • Everyday environments for ppts = high mundane realism = high ecological validity
  • Ppts unaware of involvement
• Natural experiment

  
  

  • Not in controlled environment = extraneous variables not controlled = low internal validity
  • Everyday environments for ppts = high mundane realism = high ecological validity
  • IV not directly manipulated
  • Ppts unaware of involvement
• Quasi experiment

  
  

  • Not in controlled environment = extraneous variables not controlled = low internal validity
  • Everyday environment for ppts = high mundane realism = high ecological validity
  • IV based on preexisting characteristics (not manipulated)
  • Ppts unaware of involvement