An experimental design must provide __________, so that the effects of the independent variable can be evaluated unambiguously.
A) control
B) hypotheses
C) variability
D) external validity

Question

Quizplus · Accepted Answer

Control is necessary to ensure that the effects observed are due to the manipulation of the independent variable and not any other extraneous variables. By keeping all other variables constant or controlling them, we can isolate the effect of the independent variable and evaluate its impact unambiguously. Hypotheses and variability are important, but they are not sufficient on their own to ensure that the effects are valid and reliable. External validity is related to the generalizability of the findings, but it is not directly related to the internal validity of the experiment.

An Experimental Design Must Provide __________, So That the Effects