Final answer:
Natural experiments are considered observational study designs, where researchers observe the effects of naturally occurring conditions rather than manipulating variables in a controlled environment.
Step-by-step explanation:
Natural experiments are a type of research design where the conditions are naturally occurring, and the researchers do not manipulate variables or control the environment as they would in a traditional experimental study. Instead, natural experiments fall under the category of observational study designs, whereby the researcher observes the effects of naturally varying conditions on a particular variable. This type of study is especially pertinent when experiments are not feasible due to ethical, practical, or logistical reasons.
For instance, conducting an experimental study to determine the effects of smoking on health by assigning people to smoke would be unethical. Hence, an observational study might be the best approach to assess the relationship between smoking and health outcomes. Observational studies may include larger populations and are often less expensive and easier to conduct than controlled experiments. However, they can be more subjected to confounding variables, which are factors that could affect the outcome of the study and lead to less definitive conclusions.