Researchers wanted to determine whether mothers with eating disorders expressed more negative emotions toward their first-born infants during mealtimes than mothers without eating disorders. Researchers observed how both types of mothers interacted with their first-born infants during mealtimes. The researchers found that mothers with eating disorders express more negative emotions toward their first-born infants during mealtimes than mothers without eating disorders.
a. The title of the journal article says that the study is observational. Why does that make sense?
b. Explain why it would be impossible to use random assignment in this study.
c. Describe the sample and the population.
d. What are the explanatory and response variables?
e. What is the conclusion of the study? Does it have to do with causality or only association? Explain.