Extraneous variables

• What is the definition of extraneous variables (EVs)?

  Unwanted variables affecting the DV
• What should only cause a change in the dependent variable (DV)?

  The independent variable (IV)
• What happens if extraneous variables affect the DV?

  The change in DV is due to EV, not IV
• What is the relationship between independent variables (IVs) and dependent variables (DVs)?

  • IVs are manipulated to observe effects
  • DVs are measured to assess changes
  • Only IVs should cause changes in DVs