Cliff administers his "Closeness with Family" questionnaire to a sample of children when they are 9 years old and then again when they turn 15. Cliff has done ________ research.
A) longitudinal
B) cross-sectional
C) single-strata
D) case study

Question

Quizplus · Accepted Answer

Cliff's research is longitudinal because it involves studying the same group of individuals over an extended period of time, measuring their "Closeness with Family" at two different ages (9 and 15).

Cliff Administers His "Closeness with Family" Questionnaire to a Sample