An experimental design __________.

Correct Answer: C

Rationale: An experimental design permits inferences about cause and effect because researchers evenhandedly assign people to treatment conditions. This means that researchers can manipulate certain variables and observe the effects on participants, allowing them to determine causation between variables. This is a key strength of experimental research designs. Choices A, B, and D are incorrect because they do not accurately describe the primary purpose or strength of experimental designs. Experimental designs do not focus on gathering information in natural life circumstances (A), looking at relationships between characteristics and behavior (B), or have the limitation of not being able to infer cause and effect (D).

Correct Answer: C

Rationale: Longitudinal research involves tracking the performance of each person over time. By doing so, researchers can observe common patterns in development among a group of individuals and also identify individual differences in how each person progresses over time. This methodology allows researchers to gather data on the same individuals repeatedly, offering insights into how development unfolds over the lifespan. Choices A, B, and D are incorrect because longitudinal research focuses on observing individuals over time rather than studying groups at a single point, randomly assigning participants to treatments, or conducting quasi-experiments.

Correct Answer: B

Rationale: In a cross-sectional design, researchers study groups of participants differing in age at the same point in time. This design allows researchers to compare different age groups simultaneously, providing valuable insight into age-related differences without the need to track the same group over time. Choice A is incorrect because it describes a longitudinal design where the same group is followed over time. Choice C is incorrect as it involves different groups of the same age studied at different times. Choice D is incorrect as it does not capture the essence of a cross-sectional design, which involves studying groups of different ages at the same point in time.

Correct Answer: C

Rationale: The blank in the statement refers to an approach that can be used in combination with an experimental strategy. Longitudinal and cross-sectional approaches are two common research methods in developmental psychology. Longitudinal studies involve following the same group of individuals over an extended period, while cross-sectional studies compare different groups of individuals of different ages at the same time. By combining an experimental strategy with either a longitudinal or a cross-sectional approach, researchers can gain a deeper understanding of developmental processes and changes over time. Choices A, B, and D are incorrect because correlational and sequential are not the most relevant approaches when studying developmental changes over time in research.