In trying to make sense out of the unusual experimental results, Dr. Kling and Dr. Hunger carefully reviewed a video tape of the experimental assistant interacting with the research participants. "Look at that!" said Dr. Hunger as she pointed at the screen. "He's smiling as he hands the fake vitamins to the participants in the placebo control group, but he didn't smile when he handed the real vitamins to the participants in the experimental group." "Well," said Dr. Kling, shaking his head, "It looks like we'll have to invalidate the experiment because the:
A) experimental assistant was displaying demand characteristics."
B) requirement of random assignment has been violated."
C) research assistant changed the study from a single-blind study to a double-blind study."
D) research assistant forgot to debrief the participants before handing out the vitamins."

Question

Quizplus · Accepted Answer

The experimental assistant's behavior of smiling while interacting with the placebo control group suggests demand characteristics, which means that the participants might have been able to guess the purpose of the study and alter their behavior accordingly. This would invalidate the experiment.

In Trying to Make Sense Out of the Unusual Experimental