a) experimenter effect
b) placebo effect
Correct. The placebo effect occurs when the expectations of participants influence their behavior; in this case, Angela expected the pill to make her drowsy, and that expectation—not the pill itself—made her feel drowsy.
c) subject bias
Incorrect. Angela is not biased, as she had no knowledge of the hypothesis.
d) treatment effect
Topic: The Scientific Approach
ANS: b, Apply What You Know, LO 1.9 Recall two common sources of problems in an experiment, and some ways to control for these effects., (1)
APA=2.4
TB_01_158_The Scientific Approach_Analyze_LO 1.9, APA 2.4
Two groups of graduate students were given rats and were told to teach them how to run mazes. Group 1 was told that they had “very smart” rats that should learn quickly. Group 2 was told that they had “very stupid” rats that should learn slowly. In actuality, neither group was any different, and the rats were randomly assigned. In spite of that, when the experiment concluded, Group 1 rats had learned the maze much more quickly. How can that be explained?
a) experimenter effect
Correct. The experimenter effect occurs when the participant’s performance is affected by the behavior of the experimenter. In this case, the experimenters who believed they had smart rats must have behaved in some way that boosted their rats’ performance.
b) placebo effect
c) subject bias
Incorrect. The rats were the subjects and they do not have bias.
d) treatment effect
Topic: The Scientific Approach
ANS: a, Analyze It, LO 1.9 Recall two common sources of problems in an experiment, and some ways to control for these effects., (2)
APA=2.4
TB_01_159_The Scientific Approach_Remember_LO 1.9, APA 2.4
Unintended changes in participants’ behavior due to cues inadvertently given by the experimenter are called ________.
a) replications
b) experimenter effects
Correct. The experimenter effect occurs when the participant’s performance is affected by the behavior of the experimenter.
c) volunteer biases
Incorrect. There is no such thing as volunteer bias.
d) single-blind studies
Topic: The Scientific Approach
ANS: b, Remember the Facts, LO 1.9 Recall two common sources of problems in an experiment, and some ways to control for these effects., (3)
APA=2.4
TB_01_160_The Scientific Approach_Remember_LO 1.9, APA 2.4
________ is an experiment in which participants do not know if they are in the experimental or the control group, but the experimenters do know which participants are part of which group.
a) The double-blind study
Incorrect. In a double-blind study, the experimenters would also be “blind,” meaning they would not know which participants are part of which group.
b) Field research
c) The single-blind study
Correct. The single-blind study is an experiment in which participants do not know if they are in the experimental or the control group, but the experimenters do know which participants are part of which group.
d) Correlational research
Topic: The Scientific Approach
ANS: c, Remember the Facts, LO 1.9 Recall two common sources of problems in an experiment, and some ways to control for these effects., (1)
% correct 93 a= 7 b= 0 c= 93 d= 0 r = .41
APA=2.4
TB_01_161_The Scientific Approach_Analyze_LO 1.9, APA 2.4
Double-blind studies control for ________.
a) only the placebo effect
b) only the experimenter effect
Incorrect. Double-blind studies also control for placebo effects.
c) both the placebo effect and the experimenter effect