Children's behavior on a playground is observed and later parents complete a questionnaire to compare home behavior with playground behavior of these same children. This method would be most accurately described as a 1. longitudinal design
2. descriptive design
3. correlational design
4. experimental design

3.

Explanation:

This method would be described as a correlational design.

Correlational study and design is considering a type of research where researchers are looking to understand and describe the correlation between types of relationship and what they have with one another.

Since parents from the question are looking to compare the home behavior of the children with behavior at the playground, they are using this type of method.