The improvement rate in a group of patients receiving a new behavioral therapy for obsessive-compulsive disorder is 62 percent.The improvement in the control group,who received no therapy,is 32 percent.The improvement in the control group is most likely due to:
A) the placebo effect.
B) experimenter bias.
C) participant bias.
D) inadequate experimental controls.

Question

Quizplus · Accepted Answer

The improvement in the control group is higher than what would be expected by chance alone and is therefore likely due to the placebo effect, which occurs when participants in a study experience improvement simply because they believe they are receiving a helpful treatment, even if the treatment has no active components. The other options (experimenter bias, participant bias, inadequate experimental controls) are less likely to explain the observed results in the control group.

The Improvement Rate in a Group of Patients Receiving a New