Variables, Aims + Hypotheses

• What is an independent variable?

  A variable manipulated by the researcher
• What is a dependent variable?

  A variable measured in response to changes
• What is operationalisation in research?

  • Stating variables in a testable form
  • Ensures understanding and replicability
  • Important for reliability and validity
• Why is operationalisation important in psychological research?

  It makes abstract concepts measurable
• How do psychologists make abstract variables measurable?

  By operationalising them into concrete tests
• What is an extraneous variable?

  A variable that might affect the results
• What is a confounding variable?

  An extraneous variable that varies systematically
• Why is it important to control extraneous variables?

  To ensure reliability of the results
• What are the three key considerations for controlling extraneous variables?

  1. Participant variables (e.g., age, ability)
  2. Researcher variables (e.g., behavior, appearance)
  3. Situational variables (e.g., environment consistency)
• What is the aim of a research study?

  A statement of what researchers intend to find
• What is a hypothesis?

  A testable statement about variable relationships
• What is an experimental hypothesis?

  A hypothesis predicting a significant result
• What are the two types of experimental hypotheses?

  • Directional hypothesis: predicts the direction of results
  • Non-directional hypothesis: predicts a difference without direction
• What does a null hypothesis state?

  That no significant results will be found
• How would you write a directional hypothesis about caffeine and sleep?

  Coffee drinkers take longer to fall asleep
• How would you write a non-directional hypothesis about caffeine and sleep?

  There will be a difference in sleep time
• What is the purpose of writing a hypothesis?

  To provide a testable statement for research
• What should be included when writing a hypothesis?

  • Correct type of hypothesis (directional/non-directional)
  • All levels of the independent variable
  • Fully operationalised variables
• What is a correlational study?

  A study showing relationships between variables
• What are the key differences between a test of difference and a test of correlation?

  • Correlational study has two DVs; test of difference has IV and DV
  • Correlation cannot show causation; test of difference can
  • Correlation uses ordinal variables; test of difference can use nominal data
• What is a non-directional hypothesis in correlation?

  There will be a significant correlation between variables
• What is a directional hypothesis in correlation?

  There will be a significant positive/negative correlation
• What does a null hypothesis state in correlation?

  There will be no significant correlation between variables