Control of Variables

Extraneous Variables

Any variable, other than the independent variable, that may have an effect on the dependent variable if it is not controlled. EV's are essentially nuisance variables that do not vary systematically with the IV.

Confounding Variables

Any variable, other than the IV, that may have affected the DV so we cannot be sure of the true source of changes to the DV. Confounding variables vary systematically with thr IV.

Demand Characteristics 

Any cue…