Which has the effect of reducing variance?
A)random assignment
B)matched assignment
C)holding variables constant
D)random selection

Question

Which has the effect of reducing variance?
A)​random assignment
B)​matched assignment
C)holding variables constant
D)​random selection

Quizplus · Accepted Answer

Holding variables constant reduces variance by eliminating the influence of confounding variables. Random assignment and selection are methods for increasing the likelihood of representativeness, but they do not necessarily reduce variance. Matched assignment is a method of controlling for confounding variables, but it has limitations and may not be as effective as holding variables constant.

Which Has the Effect of Reducing Variance