In an Experiment, the Purpose for Manipulating the Independent Variable

Multiple Choice

In an experiment, the purpose for manipulating the independent variable is to help ____.

A) establish the direction of the relationship by showing that the dependent variable changes when you manipulate the independent variable
B) eliminate the third variable problem because you decide when to manipulate rather than waiting for the variable to change
C) establish the direction of the relationship and help eliminate the third variable problem
D) ensure that any effects of selection bias or other randomization failures are minimized