Extraneous variables may have an influence on the dependent variable. In what ways do researchers attempt to control extraneous variables? Support your answer with current literature.

 Extraneous variables may have an influence on the dependent variable. In what ways do researchers attempt to control extraneous variables? Support your answer with current literature.

 
"Our Prices Start at $11.99. As Our First Client, Use Coupon Code GET15 to claim 15% Discount This Month!!"