Experimental method

• Independent variable is the variable we change / manipulate
• The dependent variable is what we measure
• A aim is a general statement of what the researcher intends to investigate. This is the purpose of the study.
• A hypothesis is a clear, precise, testable statement about the relationship between variables. Hypotheses can be directional or non-directional.
• A directional hypothesis (one-tailed) predicts the specific direction of the relationship or effect.
• A non-directional hypothesis (two-tailed) predicts there will be a difference or relationship but does not specify the direction.
• Operationalisation is when a variable is clearly defined in terms of how it can be measured.
• You use a directional hypothesis when:

  • There is previous research or a strong theoretical basis suggesting the direction of the expected results.
  • You predict specifically how one variable will affect another (e.g., increase or decrease).
• You use a non-directional hypothesis when:

  • There is no clear previous research, or findings have been inconsistent.
  • You simply predict that a difference or relationship exists, but not which way.