Types of experiments

• Where does a laboratory experiment take place?

  In a controlled environment
• What does the researcher manipulate in a laboratory experiment?

  The independent variable (IV)
• What is recorded in a laboratory experiment?

  The effect of the IV on the DV
• What must be controlled in a laboratory experiment?

  All other variables
• What are the advantages of laboratory experiments?

  • High control over extraneous variables
  • More certainty about IV causing DV effects
  • Replication is possible
• What are the disadvantages of laboratory experiments?

  • Lack of generalisability
  • Demand characteristics present
  • Low mundane realism
• What is an example of a laboratory experiment?

  Asch’s line study
• Where does a field experiment take place?

  In a natural environment
• What does the researcher manipulate in a field experiment?

  The independent variable (IV)
• What is recorded in a field experiment?

  The effects of the IV on the DV
• What are the advantages of field experiments?

  • Higher mundane realism
  • More valid and authentic environment
• What are the disadvantages of field experiments?

  • Lack of control over extraneous variables
  • Difficult to establish cause and effect
  • Difficult replication
  • Ethical issues with consent
• What is an example of a field experiment?

  The bystander effect
• What characterizes a natural experiment?

  Pre-existing independent variable
• How does the independent variable change in a natural experiment?

  It changes naturally, not manipulated
• What is recorded in a natural experiment?

  The effects of the IV on the DV
• What are the advantages of natural experiments?

  • Opportunities for research not otherwise possible
  • High external validity
• What are the disadvantages of natural experiments?

  • Rare naturally occurring events
  • No random allocation to conditions
• What is an example of a natural experiment?

  Rutter: Romanian orphans
• What characterizes a quasi-experiment?

  IV based on existing differences
• How is the independent variable treated in a quasi-experiment?

  No manipulation by the researcher
• What are the advantages of quasi-experiments?

  • Often conducted under controlled conditions
  • Similar strengths to laboratory experiments
• What are the disadvantages of quasi-experiments?

  • No random allocation to conditions
  • Potential confounding variables
• What is an example of a quasi-experiment?

  Studying people with phobias