Question

In a study of 900 European American children born in 1991 (“Maternal Employment and Child Cognitive Outcomes in the First Three Years of Life: The NICHD Study of Early Child Care,” Brooks-Gunn, Han, and Waldfogel, Child Development 73[2002]: 1052-1072), the authors wrote “children whose mothers worked at all by the ninth month of their life had lower [cognitive outcome] scores at 36 months than did children whose mothers did not work by that time.” These results were statistically significant.

1. What is the response variable in this study?

A) The age of the child.

B) The cognitive outcome score of the child at 36 months.

C) The working history of the mother (did or did not work during the first nine months of the child’s life).

D) None of the above

2. What is the explanatory variable in this study?

A) The age of the child.

B) The cognitive outcome score of the child at 36 months.

C) The working history of the mother (did or did not work during the first nine months of the child’s life).

D) None of the above.

Answer 1

1. Response variable is a variable dependent on one or more other independent variables known as 'explanatory variables'. Here, in this study, we see that Child cognitive outcome is dependent on the working history of the mother. Hence the variable 'Cognitive outcome score of the child at 36 months' is a response variable here. Thus, option (B) is correct.

2. Explanatory variables, as the name says, is a variable which is independent and explains the behavior of the response variable. Here, in this study, we see that the working history of the mother during the first 9 months of the child's life is explaining the child's cognitive outcomes, thus 'the working history of the mother' is an explanatory variable here. Hence, option (C) is correct.