PrepTest 132, Section 2, Question 9
A retrospective study is a scientific study that(61 more words not shown)
Which one of the following,(10 more words not shown)
- AWhether or not(35 more words not shown)
- BA retrospective study(30 more words not shown)
- CIn studies of(32 more words not shown)
- DIf a study(24 more words not shown)
- EEvery scientific study(31 more words not shown)
Reading the argument
Think of researchers asking people with the same illness about their earlier lives. Did they smoke? Did they live in similar places? A retrospective study looks backward for connections that might help explain what is true of those people now.
But how accurately can people report their own pasts? Someone might forget what happened years ago without trying to deceive anyone. That gives me a concern about the evidence. It doesn't yet establish the author's strong conclusion that these studies cannot reliably identify causes.
What we’re looking for
The argument moves from “must use people's reports” to “cannot reliably determine causes.” Why does using those reports create that problem? The assumption needs to supply the missing concern about the reports' accuracy. We want a reason their required evidence can't be relied on, not merely a statement that researchers have to collect it.
Working the answers
- A
“May depend at least in part” is too weak to establish the conclusion. This says accuracy might matter to a study's reliability. It doesn't tell us that the reports these studies must use are inaccurate or especially prone to error. The missing problem with those reports remains missing.
- B
This gives a requirement for reliably determining causes: there must be correlations between present characteristics and past events. But it doesn't tell us that those correlations are absent. We cannot establish failure by naming a requirement without showing that the study fails to meet it. Nor does B establish the problem with personal reports.
- CCorrect
The reports these studies rely on are highly susceptible to inaccuracy. That supplies the missing reason to distrust a method that must use those accounts to connect present characteristics with past events.
“Susceptible” doesn't mean every reported detail is false. Someone could accurately remember plenty of things and still provide evidence too vulnerable to mistakes to support a reliable determination of causes. C addresses that reliability concern directly.
- D
This tells us what follows if a study uses only accurate reports. It doesn't establish that retrospective studies meet that condition, or that their reports are unreliable. A person's own account could be accurate; “self-report” doesn't automatically mean “false.” We still need a reason to doubt the reports used here.
- E
The passage already says retrospective studies of humans must use their subjects' reports. Extending that requirement to every study fitting this description doesn't explain why the reports create a reliability problem. Repeating or broadening the need to use them is no substitute for establishing their weakness.
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