Experimental method

• What are aims?

  General statements that describe the purpose of an investigation.
• What is a hypothesis?

  A statement that is made at the start of a study and clearly describes the relationship between variables.
• What is a directional hypothesis?

  A directional hypothesis states whether changes are greater or lesser.
• What is a non-directional hypothesis?

  A non-directional hypothesis states there is a difference between conditions but doesn’t state the direction of the difference.
• When do researchers use a directional hypothesis?

  When a theory or the findings of previous research suggests a particular outcome.
• When do researchers use a non-directional hypothesis?

  When there is no theory or previous research from earlier studies.
• What is the relationship between the independent and dependent variables?

  Researchers change or manipulate the independent variable and records or measures the effect of this change on the dependent variable.
• Why do all other variables need to remain constant?

  So the researcher can be confident that any change in the dependent variable, was only due to the independent variable.