A researcher examines the relationship between the quality of breakfast and academic performance for a group of elementary-school children. For each child, the researcher interviews the parents to obtain information about the child's typical breakfast, and uses school records to obtain a measure of academic performance.
a. Explain why this study is not a true experiment.
b. Describe how the study could be modified to make it into an experiment that investigates whether the quality of breakfast has a direct effect on academic performance for elementary-school children. (Note: Your experiment may raise ethical questions that would make it very unlikely that the study could actually be conducted.)