Testing Hypotheses

• Hypothesis


  A proposed explanation for a phenomenon, which can be tested through further investigation
• Testing Hypotheses


  1. Identify variables

  2. Determine independent variable

  3. Determine dependent variable

  4. Determine extraneous variables
• Independent Variable (IV)


  The variable that researchers manipulate in order to test its effect on the dependent variable (outcome)
• Levels of Independent Variable

  Multiple experimental conditions of the independent variable
• Levels of Independent Variable

  • 3 different studying techniques
  • Low, medium, high advertising spend
  • Real medication, placebo
• Dependent Variable (DV)


  The outcome or effect being measured within the study
• Dependent Variable


  • Exam score
  • Sales
  • Blood pressure
• Extraneous Variable


  A third variable that may unknowingly be affecting the outcome of the study (the DV)
• Extraneous Variables


  • Can be situational variables (present in the environment) or participant variables (abilities, attributes and tendencies of participants)
  • When an extraneous variable is found to affect the outcome of the study, it becomes a confounding variable
• Controlling Extraneous Variables


  1. Use standardised procedures

  2. Use counterbalancing

  3. Use randomisation

  4. Use single-blind or double-blind techniques

  5. Use same participants in both conditions or match participants on important characteristics
• The effect of music on people's ability to study

  Independent Variable, Dependent Variable, Extraneous Variable
• The effect of sleep on exam scores

  Independent Variable, Dependent Variable, Extraneous Variable
• The relationship between gender and conformity

  Independent Variable, Dependent Variable, Extraneous Variable
• The relationship between IQ and memory

  Independent Variable, Dependent Variable, Extraneous Variable