For a third variable to be plausible as the explanation in an established association, which of the following must also be true?
A)The third variable must be related to both of the measured variables in the original association.
B)The third variable must be measured on the same scale as the original measured variables.
C)The third variable must be a categorical variable.
D)The third variable must have a positive relationship with the two measured variables in the original association.

Question

Quizplus · Accepted Answer

In order for a third variable to be a plausible explanation for an established association, it must be related to both of the measured variables. This means that the third variable must be correlated with both the independent and dependent variables in the original association. The third variable does not necessarily need to be measured on the same scale or be a categorical variable, nor does it need to have a positive relationship with the measured variables.

For a Third Variable to Be Plausible as the Explanation