​The major difference between longitudinal studies and cross-sectional studies is that cross-sectional studies occur ___________ whereas longitudinal studies occur _______________.

A) ​once; over time
B) ​over time; once
C) ​with the same participants; with different participants
D) ​with the same participants; over time

Longitudinal Studies

Research designed to observe the same subjects over a period of time, allowing for the study of changes and developments.

Cross-Sectional Studies

Research designs in which subjects of different ages are studied at one point in time.

Developmental Trends

Describes the patterns and directions of growth, change, or progress in any developmental aspect over a period.