AP PSYCHOLOGY

Detailed explanation-1: -Four major design types with relevance to user research are experimental, quasi-experimental, correlational and single subject. These research designs proceed from a level of high validity and generalizability to ones with lower validity and generalizability.

Detailed explanation-2: -Natural experiment studies (NES) combine features of experiments and non-experiments. They differ from planned experiments, such as randomized controlled trials, in that exposure allocation is not controlled by researchers.

Detailed explanation-3: -Natural experiments are observational studies which can be undertaken to assess the outcomes and impacts of policy interventions. They are often possible where there is a divergence in law, policy or practice between nations, regions or other political, jurisdictional or social units.

Detailed explanation-4: -Correlational research is considered non-experimental because it focuses on the statistical relationship between two variables but does not include the manipulation of an independent variable.