Types of Variables

  • Dependent variable (DV) = measured
  • Independent variable (IV) = manipulated
  • Controlled variable (CV) = kept constant
  • Extraneous variable (EV) = anything other than the IV that could affect the DV – individual differences
  • Confounding variable = EVs have that already affected the DV, since they were not controlled

Operationalisation: making a concept measurable for testing as a variable in a hypothesis