Answer:
This is an example of a Cross-sectional Design.
Step-by-step explanation:
. Cross-sectional research involves using different groups of people who differ in the variable of interest but share other characteristics, such as socioeconomic status, educational background, and ethnicity.
A researcher could also observer various subjects of different aspects such as age in a specific point in time, in order to observe the differences within the subjects.
In this case, we can clearly see it is this type of design since the researcher interviews children from ages 5, 9 and 13 in one specific moment in time about their depresive symptoms. This is also different age groups with the same characteristics.