What is the third-variable problem?
a. When a researcher measures so many variables that it's difficult to make sense of the data.
b. When a research considers only one direction of causation between two variables that are strongly correlated.
c. When a researcher measures variables that are not relevant to the relationship he or she is most interested in.
d. When a researcher fails to consider that two variables may be correlated due only to the effects of some unmeasured third variable.
Question 2
If the hypothesis states that A causes B and the r statistic demonstrates that A and B have a correlation of 0, it can be concluded that
a. A causes B.
b. B causes A.
c. A does not cause B.
d. none of the above