PrepTest 116, Section 3, Question 22
Taking advanced mathematics courses should increase a student's(37 more words not shown)
The flawed pattern of reasoning(15 more words not shown)
- AFur color is(31 more words not shown)
- BWater can cause(23 more words not shown)
- CEating a diet(23 more words not shown)
- DBuying running shoes(35 more words not shown)
- EReading to children(41 more words not shown)
Reading the argument
Maybe these students already get good grades. The students who choose advanced math may be especially interested in school or academically strong before the course begins. Their grades wouldn't show that taking the course made them stronger students.
The study compares two groups: people who have taken advanced math and people who haven't. The conclusion turns that difference into advice about what taking a course should do to a student's GPA. That jump needs support. A feature of the students could help explain both their course choices and their grades.
What we’re looking for
For the parallel flaw, look for another case where people who choose an activity already tend to have the trait the activity supposedly produces. We want to ask, 'Did doing this create the difference, or did people who were already different choose to do it?' The comparison and the direction of the proposed explanation both matter.
Working the answers
- A
This links parents' fur colors with their kittens' colors as evidence of inheritance. It doesn't describe animals choosing something because they already have the trait that the choice supposedly causes. Whatever further questions we could ask about inheritance, this isn't the same selection problem as strong students choosing advanced math. We don't need to declare A beyond criticism to reject it as the closest match.
- B
The water is mixed with alcohol in every example. Perhaps the scotch, whiskey, or other alcohol causes the intoxication. That is a mistake about which ingredient produces an effect. It doesn't compare people who choose an activity with people who don't, then overlook why those groups might differ already.
- C
'May cause weight gain in some people' is a much more cautious conclusion than saying taking a course should raise a student's GPA. The evidence also only describes the diets of many overweight people; it doesn't compare their diets with those of other people. C shares a broad concern about inferring a cause, but misses important pieces of the original pattern.
- DCorrect
Frequent exercisers may buy more running shoes because they use them more. Buying the shoes needn't be what gets them exercising. The shoe buyers correspond to the advanced-math students, and frequent exercise corresponds to high grades. In each case, the author sees a difference between groups and assumes choosing the activity will produce that difference in a person.
- E
This is tempting because it also uses a comparison to support a causal claim. But the proposed cause happens early and the interest in independent reading comes later. A child's later reading can't make someone read to that child earlier in time. Other explanations could still exist, such as a family's interest in books, but E doesn't offer D's close match to people choosing something because of an existing tendency.
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