Which of the following describes a sequential design? studying a group of five-year-olds over a 10-year period measuring motor abilities of a child when she is two years old and then measuring her abilities again when she is five years old comparing reasoning abilities of five-, eight-, and 10-year-olds studying groups of 10- and 15-year-olds and then studying these individuals two, four, and six years later

Studying groups of 10- and 15-year-olds, and then studying these individuals 2, 4, and 6 years later

Explanation:

Sequential design

In this type of research design, the researcher uses or follow a sequence of samples  usually two or more groups and thereafter takes data on them later on. it is simply a gathering or combination of the other designs. it is often said to have the same problems as longitudinal and cross-sectional strategies but its design itself helps recognizes difficulties in the research. The researcher that uses this design is often interested in age-related changes in children's problem-solving skills and thereafter selects three samples-preschool-age children, school-age children, and adolescents - and follows them for five years.

Sequential design advantages

1. It uses both the strength of  cross-sectional and longitudinal designs

2. It is said to reduce confounding of age, cohort, and time measurement effects.

Sequential design disadvantages

1. It is usually complex in nature

2. It is also time consuming

3.  it is very expensive to manage/

i got 3,4 and 5 as an answer