36 A researcher studies language development by selecting a sample of two-year-old children and giving them a language skill test. Each year for the next two years, the children are brought back and...

36

A researcher studies language development by selecting a sample of two-year-old children and giving them a language skill test. Each year for the next two years, the children are brought back and tested again. The researcher plans to compare the children's scores at age two, age three, and age four. This study is an example of a(n)

a. time-series design

b. interrupted time-series design

C. cross-sectional developmental design

d. longitudinal developmental design