Types of Experiments

• What are the four types of experimental methods?

  Lab, Field, Natural and Quasi
• What is a lab experiment?

  An experiment that take place in a highly controlled environment (doesn't have to be a typical lab). The researcher manipulates the IV and records the effects of it on the DV. Maintains strict control of extraneous variables.
• Describe a field experiment.

  This takes place in a natural setting. The researcher manipulates the IV and records the effect on the DV
• Describe a natural experiment

  The change in the IV is not brought about by the researcher, but would have happened even if the researcher had not been there. The researcher records the effects of the IV on the DV
• Describe a quasi experiment.

  A stud that is almost an experiment but lacks key ingredients. The IV hasn't been determined by anyone - the variables simply exist, such as being old or young, male or female. Strictly speaking this in not an experiment.
• Give two strengths of a lab experiment

  High level of control over extraneous variables -> High internal validity. Possible replication -> demonstrates reliability
• Give two strengths of a field experiment.

  Possible to generalise findings. High mundane realism. Low risk of demand characteristics
• Give two strengths of a natural experiment

  Low risk of ethical issues. Possible to generalise findings due to real life issues
• Give a strength of a quasi experiment

  Controlled conditions -> replicable -> high internal validity
• Give two weaknesses of a lab experiment

  Low mundane realism due to artificial environment. High risk of demand characteristics due to high control
• Give two weaknesses of a field experiment

  Low level of control over extraneous variables - not replicable. High risk of ethical issues - likely no informed consent.
• Give two weaknesses of a natural experiment

  difficult to generalise - natural occurring events may be rare. Low control - not replicable.
• Give a weakness of a quasi experiment

  Can't randomly allocate participants to conditions - confounding variables may be present - harder to conclude that IV caused DV
• What is the difference between a quasi experiment and a natural experiment?

  In a quasi experiment the IV hasn't been determined by the researcher, it's naturally occurring. In a natural experiment the IV would occur if the researcher wasn't present.