Answer:
Type of play group is the independent variable;
No play group is the control group
Step-by-step explanation:
In a typical research design, the independent variable is the variable that is being manipulated or changed in order to measure or observe the changes it has in the dependent variable.
The dependent variable is the variable that is measured. It is the variable that changes as a result of the effect of the independent variable.
From the question above, the independent variable is the type of play group, and the dependent variable is the preference the 5th-graders have, which is dependent on the type of play group they belong to.
The control group is the group that is used as a standard for comparison to ascertain the effect of the treatment in a research study. The control group in the above study is the no play group.