Types of Experiment

• Lab Experiment:

  • This type of experiment is conducted in a well-controlled environment and therefore is accurate and objective measures can be taken.
  • The researcher decides where the experiment will take place, and when.
  • A standardised procedure.
• Lab Experiment AO3: Strength:

  • High degree of control experimenters control all the variables.
  • Replication is easy and researchers can check results to increase reproducibility.
• Lab Experiment AO3: Weakness:

  • Experimenter bias which can affect results and participants may be influenced by these expectations.
  • Low ecological validity because the high degree of control makes the situation artificial.
• Field Experiment:

  • These are conducted in everyday environments; however, the situations are artificially set up.
  • The experimenter still manipulates the IV, but because it is in a real-life setting, it is harder to control extraneous variables.
• Field Experiment AO3: Strength:

  • Naturalistic so more natural behaviours create high ecological validity.
  • Controlled IV.
• Field Experiment AO3: Weakness:

  • Ethical considerations due to the invasion of privacy and it is likely to not have informed consent.
  • Loss of control over extraneous variables hence precise replication not possible.
• Natural experiment:

  • Natural experiments are when naturally occurring IV is investigated that isn’t deliberately manipulated.
• Natural Experiment AO3: Strength:

  • Provides opportunities for research that would have been impossible due to practical reasons.
  • High external validity as you are dealing with real life issues.
• Natural Experiment AO3: Weakness:

  • Natural occurring events may be rare so these experiments are not replicable so it is hard to generalise findings.
  • Very difficult to randomise so extraneous variables become a problem.
• Quasi Experiment:

  An experiment whereby the IV has not been determined by the researcher, instead it naturally exists e.g. age, or gender.
• Quasi Experiment AO3: Strength:

  • Controlled conditions, hence replicable.
  • High internal validity.
• Quasi Experiment AO3: Weakness:

  • Cannot randomly allocate participants to conditions so there may be confounding variables.
  • Harder to conclude that the IV caused the DV.