Research issues

• Extrenuos variables

  When something else influences the DV

  e.g. poor lighting, age of pps
• Confounding variables

   Another IV variable is created due to chance, e.g someone on the way to experiment saw a celeb
• Demand characteristics

  Pps try to work out what is going on, the clues that give them what's going on are the demand characteristics
• Why are demand characteristics a problem?

  They can change how pps behave