Describe laboratory, field, and natural, or quasi-, experiments. Explain the strengths and limitations of each

What will be an ideal response?

In a laboratory experiment, the investigator manipulates an independent variable in controlled laboratory conditions and looks at its effect on the dependent variable. A laboratory experiment requires random assignment of participants to treatment conditions. The strength of the laboratory experiment is that it permits inferences about cause-and-effect relationships. The limitation of the laboratory experiment is that findings may not generalize to the real world. In a field experiment, the investigator randomly assigns participants to treatment conditions in natural settings. Its strength is that it permits generalization of experimental findings to the real world. A limitation of the field experiment is that control over the treatment is generally weaker than in a laboratory experiment. In a natural, or quasi-, experiment, the investigator compares already existing treatments in the real world, carefully selecting groups of participants to ensure that their characteristics are as much alike as possible. The strength of the natural experiment is that it permits many real-world conditions that cannot be experimentally manipulated. A limitation of the natural experiment is that findings may be due to variables other than the treatment.