A researcher conducts a study and concludes that a new behavioral health treatment program significantly reduces one's risk for disease compared with risk levels in the general population (d = -0.64).Interpret the size of this effect.
A) 64% of the variability in risk level can be accounted for by the new treatment.
B) 64% of the new treatment can be accounted for by the risk levels.
C) Risk levels in the population shifted 0.64 standard deviations below the mean.
D) Risk levels in the population shifted 0.64 standard deviations above the mean.

Question

Quizplus · Accepted Answer

The effect size (d = -0.64) indicates that the risk levels in the population who received the new treatment shifted 0.64 standard deviations below the mean risk levels of the general population, not above it or explaining variability or causation percentages.

A Researcher Conducts a Study and Concludes That a New