Groups of people differing in age (or other attribute) are studied at the same point in time.

Groups of people differing in age (or other attribute) are studied at the same point in time.

• A. Cross-sectional design
• B. Longitudinal design
• C. Experimental design
• D. Case study

Answer: (A)

When you study groups that differ in age (or another attribute) at the same point in time, you’re using a cross-sectional design. This approach provides a snapshot, letting you compare different groups side by side to see how they differ at that moment. It’s efficient and quick, since you don’t have to follow people over years. But be mindful of cohort effects—differences between groups might reflect generational experiences rather than aging itself. In contrast, a longitudinal design follows the same individuals over time to observe how they change, an experimental design involves manipulating a variable with random assignment, and a case study focuses on detailed information from one person or a small group.

When you study groups that differ in age (or another attribute) at the same point in time, you’re using a cross-sectional design. This approach provides a snapshot, letting you compare different groups side by side to see how they differ at that moment. It’s efficient and quick, since you don’t have to follow people over years. But be mindful of cohort effects—differences between groups might reflect generational experiences rather than aging itself. In contrast, a longitudinal design follows the same individuals over time to observe how they change, an experimental design involves manipulating a variable with random assignment, and a case study focuses on detailed information from one person or a small group.