The only control technique that can account for both known and unknown sources of extraneous variation ise.g., within designs require fewer participants, offer better control, but also may demand too much participant time and offer clues to the researcher's hypothesis).
A) precision control.
B) matching by yoked control.
C) random selection.
D) random assignment.

Question

Quizplus · Accepted Answer

Random assignment is the only control technique listed that can account for both known and unknown sources of extraneous variation by ensuring that each participant has an equal chance of being assigned to any group in the study, thus balancing out these variations across the groups.

The Only Control Technique That Can Account for Both Known