15. (FACTUAL-21) THE DUKE STUDIES OF AGING INVOLVED THE SELECTION OF...

1-15. (factual-21) The Duke studies of aging involved the selection of separate groups of adults

aged 45, 50, 55, 60, and 65. Each group was then retested at 2-year intervals for a total of 6

years. This is an example of what general type of research design?

a. longitudinal

b. panel

*c. sequential

d. cross-sectional