PrepTest 138

Incorrect. The author rejects the opposing point because it lacks scientific backing, not because it's made by a group that's likely to be biased, so this argument doesn't feature an ad hominem flaw as this answer suggests. While the group making the claim is likely to be biased, the author never brings that up.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Ginseng tea companies - Our ginseng tea reduces stress
Rebuttal - No studies prove ginseng relieves stress
Conclusion - The tea doesn't reduce stress

Answer Anticipation:
There's a feature of this argument that suggests a specific flaw, and it's not the study! Generally, a study would suggest a sampling flaw, or a correlation/causation flaw. However, the studies aren't highlighted with enough specificity to analyze them for a flaw—their results are presented as fact.

No, the feature we have here is a conclusion that states that an opposing point is wrong/their conclusion is false. When the author of an argument reaches the polar opposite conclusion of the opposing point, you should check for an absence of evidence flaw—does the author present evidence to prove the opposite conclusion, or does she simply point out a flaw in the opposing point and then conclude that they're wrong?

If an argument for a given conclusion is faulty, that doesn't mean the conclusion is false—you can make a bad argument for a true statement (a ridiculous e.g., chocolate chip cookies are delicious, so the Earth is round. That's a bad argument but a true conclusion).

Here, the author points out that no studies support the opposing point and concludes that their conclusion must be false. That's an absence of evidence flaw, as there's no positive evidence that ginseng doesn't relieve stress, as that conclusion implies.

Answer Explanation:
This answer describes an absence of evidence flaw, which we identified as being present. The argument concludes that ginseng tea doesn't relieve stress—that a claim it does is false—based on studies not establishing that it does.

Key Takeaway:
When an argument reaches a conclusion that an opposing point is wrong, or its conclusion is false, then check to see if that's based on a fault in the argument, thus leading to an absence of evidence flaw. Note that the argument's conclusion has to state that the opposing point is wrong/false for it to be an absence of evidence flaw—if the argument instead concludes the opposing point might be wrong, or doesn't prove its conclusion, this flaw won't apply.

Incorrect. There is a set of scientific studies mentioned, but there's no specific discussion of the sample in any of these studies, so we can't say that the samples are likely to be unrepresentative.

Incorrect. The argument is about whether the tea relieves stress. Even though it brings up that "many people" buy the tea for health reasons, that doesn't factor into the argument meant to show that these teas don't relieve stress.

Incorrect. The claim isn't that the tea relieves stress, but rather that the ginseng in the tea counteracts the effects of stress. This answer would be correct if the tea companies claimed their tea relieved stress and the author focused on just one ingredient.