A pharmaceutical company has developed a new ADHD medication and wishes to test its effectiveness. Identify the threats that validity researchers might face in an experimental test of the medication's efficacy and suggest how these threats may be overcome.

Question

What will be an ideal response?

Answer 1

The answer should include the following information:

Validity researchers might face the following threats:

a. Participant expectations: Participants should not know whether they receive the medication or not, so that the apparent effects of the drug do not reflect the participants' belief in its efficacy. A placebo should be given in the no-medication group.
b. Experimenter expectations: The experimenter should not know which participants receive the medication so that the apparent effects of the drug do not reflect the experimenter's belief in its efficacy. A double-blind procedure should be used.
Psychologists typically use a procedure in which all the participants receive a treatment, but those in the control group receive only a placebo, a false treatment, such as a pill, "drug," or other substance, that has no significant chemical properties or active ingredient. Because members of both groups are kept in the dark about whether they are getting a real or a false treatment, any differences in outcome can be attributed to the quality of the drug and not to the possible psychological effects of being administered a pill or other substance.

However, there is one more safeguard that a careful researcher must apply in an experiment such as this one. To overcome the possibility that experimenter expectations will affect the participant, the person who administers the drug should not know whether it is actually the true drug or a placebo. By keeping both the participant and the experimenter who interacts with the participant "blind" to the nature of the drug that is being administered, researchers can more accurately assess the effects of the drug. This method is known as the double-blind procedure.