For which of the following types of studies is it impossible to draw cause-and effect conclusions? I). Completely randomized experiments
II)) Randomized block experiments
III). Observational studies
A)I only
B)II only
C)III only
D)It is never possible to draw cause-and-effect conclusions.
E)It is always possible to draw cause-and-effect conclusions.

Question

Quizplus · Accepted Answer

Cause-and-effect conclusions can generally be drawn from completely randomized experiments and randomized block experiments because these designs involve the manipulation of variables and random assignment, which helps control for confounding variables. Observational studies, however, do not manipulate variables or assign subjects randomly, making it difficult to establish causality due to potential confounding factors.

For Which of the Following Types of Studies Is It