Experimental _________ is achieved through introduction and withdrawal, staggered introduction, or iterative manipulation of the independent variable.

• A. Manipulation
• B. Baseline
• C. Control
• D. Treatment

Answer: (C)

Control in experimental design means ensuring that changes in the dependent variable are caused by the independent variable, not by other factors. This is achieved by managing when and how the IV is present. Introducing and withdrawing the IV creates a reversible condition: if the dependent variable changes when the IV is on and returns to baseline when it is off, you can attribute the change to the IV. Staggered introduction across participants or behaviors helps show that the timing of the effect follows the IV and not some external factor that differs across subjects. Iterative manipulation—adjusting the IV in steps—lets you observe a dose–response or gradual effects, strengthening the argument that the IV is driving the outcome. Together, these approaches establish experimental control and support causal conclusions.baseline refers to the initial measurement period before intervention and is part of the design, but it doesn’t by itself establish control; manipulation is the act of changing the IV, not the mechanism for demonstrating control; treatment is the IV itself, not the method of achieving controlled observation.