In a longitudinal design age is treated as a __________ variable, but age is treated as a ____________ variable in a cross-sectional design.
A) within-subjects / within- and between-subjects
B) within- and between-subjects / between-subjects
C) within-subjects / between-subjects
D) between-subjects / within-subjects
(e) between-subjects / between-subjects

Question

Quizplus · Accepted Answer

In a longitudinal design, age is a within-subjects variable because the same subjects are observed over time. In a cross-sectional design, age is a between-subjects variable because different age groups are compared at one point in time.

In a Longitudinal Design Age Is Treated as a __________