"Surprising" Phenomenon
Why did approximately 80 percent of people in each of the study’s groups report relief from insomnia during the first two weeks of the study and 90 percent of those from each group who reported relief from insomnia claim their insomnia returned during the third week?
Objective
The right answer will be a hypothesis that explains a key similarity between the 80 percent of people from both the placebo and treatment groups that reported relief from insomnia, the 90 percent of those from each group that reported relief but claimed their insomnia returned, or both.
A
Because it is easy to build up a tolerance to the new drug, most people will no longer experience its effects after taking it every night for two weeks.
This provides a difference between the people in the placebo and treatment groups, but we need a similarity. (A) tells us most people in the treatment group wouldn’t experience the drug’s potential effects after two weeks. This doesn’t explain why the groups had similar results.
B
The psychological comfort afforded by the belief that one has taken a sleep-promoting drug is enough to prevent most episodes of insomnia.
We don’t know if people in either group believed that they’d taken a sleep-promoting drug. Therefore, (B) is irrelevant.
C
The new drug is very similar in chemical composition to another drug, large doses of which have turned out to be less effective than expected.
We don’t know the significance of the chemical composition of the new drug or the size of the dosage taken by people in the treatment group. (C) doesn’t help explain the phenomenon in the stimulus.
D
Most insomniacs sleep better in a new environment, and the new drug has no effect on an insomniac’s ability to sleep.
This points out two key similarities between those in the placebo and treatment groups. Most people in both groups were likely to sleep better in their new environment and the new drug doesn’t affect sleep, helping to explain the similarity in results between the two groups.
E
Some insomniacs cannot reliably determine how much sleep they have had or how well they have slept.
We don’t know if this applies to insomniacs in the study. (E) tells us nothing about why the placebo and treatment groups had similar results.
Summarize Argument
The author concludes that most people only need 50 weekly behavioral therapy session in order to clear up the psychological problems they have. This is based on a study in which researchers measured how quickly 60 different psych. problems cleared up among a sample of people who had weekly therapy sessions. 75% of the 60 problems cleared up within 50 weeks.
Identify and Describe Flaw
The author overlooks the possibility that most people have a psych problem that takes longer than 50 weeks to clear up. The fact 45 out of 60 types of psych. problems clear up in 50 weeks doesn’t tell us whether most people with a psych. problem have one of those 45 problems. Most might have one of the 15/60 that takes longer than 50 weeks.
A
takes for granted that there are no psychological problems that usually take significantly longer to clear up than the 60 psychological problems studied
The author doesn’t assume that there’s no problem that takes longer to clear up than the 60 studied. She only needs to assume that if those problems exist, most people do not have those longer-to-clear-up problems.
B
fails to address the possibility that any given one of the 60 psychological problems studied might afflict most people
The author assumed that most people have one of the 45 problems that cleared up within 50 weeks. But this overlooks that most people might have one of the 15 problems that took longer to clear up.
C
takes for granted that no one suffers from more than one of the 60 psychological problems studied
Even if you think having multiple problems could require more than 50 weeks to clear up, the author doesn’t have to assume “no one” has more than one problem. She would only need to assume that most people don’t have more than one problem.
D
fails to address the possibility that some forms of therapy have never been proven to be effective as treatments for psychological problems
We know that certain problems cleared up with weekly behavioral therapy sessions. So, there’s evidence that behavioral therapy works. Also, the author doesn’t conclude that any kind of therapy will be enough for most people; she specifies behavioral therapy.
E
takes for granted that the sample of people studied did not have significantly more psychological problems, on average, than the population as a whole
The study concerns the time required for various psychological problems to clear up. Whether the sample had more problems than average is irrelevant, because we can still measure the clear-up rate of the problems present in the sample.