Which of the following is an example of "present versus absence" variation of the independent variable?
A) All participants' reaction times are measured after ingesting two beers
B) In a study of distraction on reading comprehension, one group is distracted by noise, another by a flashing light, and a third by a bad odor
C) The control group gets no drug, one experimental group gets 5 mg/kg of a drug, and a second experimental group gets 10 mg/kg of the drug
D) An experimental group receives 5 mg/kg of a drug and the control group receives no drug (placebo)

Question

Quizplus · Accepted Answer

In "present versus absence" variation, one group receives the treatment (present) and the other does not (absence), as in option D where the experimental group receives the drug and the control group receives a placebo.

Which of the Following Is an Example of "Present Versus