Variables

• What is an independent variable?

  The variable we change in an experiment
• How does the independent variable affect the dependent variable?

  It is changed to observe its effect
• What is a dependent variable?

  The variable that is measured in research
• What happens to the dependent variable when the independent variable changes?

  It is affected by changes in the independent variable
• What is an extraneous variable?

  A variable not being investigated in research
• How can extraneous variables affect research outcomes?

  They can potentially affect the outcome of a study
• What is a confounding variable?

  A type of extraneous variable that varies systematically
• Why is it difficult to determine the effect of the independent variable when a confounding variable is present?

  Changes in the DV may be due to either variable
• What does operationalisation involve?

  Clearly defining variables for measurement
• Give an example of operationalisation.

  Measuring weight in kilograms gained
• What are the key differences between independent, dependent, extraneous, and confounding variables?

  • Independent Variable: Changed to observe effects
  • Dependent Variable: Measured outcome of the study
  • Extraneous Variable: Not investigated but can affect results
  • Confounding Variable: Systematically varies with the IV, complicating results