Which of the following is a reason why a researcher might choose to conduct a double-blind placebo control group study?
A)To eliminate testing effects
B)To control for observer bias
C)To prevent attrition
D)To control for regression to the mean

Question

Quizplus · Accepted Answer

Double-blind placebo control group studies are used primarily to control for observer bias. This occurs when the researchers' expectations or beliefs regarding the treatment inadvertently influence the study's outcome. By using a double-blind design, neither the participant nor the researcher knows which group is receiving the treatment or the placebo, which reduces the potential for observer bias. None of the other choices are reasons for using a double-blind placebo control group study: A) eliminating testing effects refers to the order in which participants receive the treatment and placebo, which is not controlled by a double-blind design; C) attrition is the loss of participants from a study, which is not controlled by this type of design; and D) regression to the mean refers to the tendency for extreme scores to move closer to the average on subsequent measurement, which is not directly controlled by the study design but can be controlled through randomization and a large sample size.

Which of the Following Is a Reason Why a Researcher