Question

In an experiment to see if the comfort of chairs in a classroom makes a difference in how long students will work on math problems, one group was in standard chairs, and one group was in padded, comfortable chairs. What is the dependent variable in this experiment?
A.How long students worked on the math problems

B.The comfortable chairs

C.The difficulty of the math problems

D.The standard chairs

Answer 1

The correct answer is A.

The dependent variable is: how long students worked on the math problem. Secondly, the goal of the study is to assess whether an explanatory variable (the confort of chairs) does have a causal effect on the lenght of math study or not.  

As it is described in the question, the explanatory variable is a binary one: it takes value equal to 1 for the group seated in padded, comfortable chairs, and value 0 for the individuals in the group with standard chairs. Therefore, the study can be understood as the assesment on the validity of a treatment, on its capacity to make a difference on the dependent variable.