Research indicates that 90 percent

Answer choices

1. A

   Doesn't Fail to Consider12% picked this

   It fails to acknowledge the possibility that Tom is among the 10 percent of people who drink large amounts of coffee

   The author acknowledges this possibility by saying "Tom is quite likely an extreme insomniac". If the author had concluded, "thus Tom is definitely an extreme insomniac", then she would be failing to acknowledge that a 90% statistic (even if misread, as the author is doing) would not prove certainty.

   12%
2. B

   Out of Scope: causes7% picked this

   It fails to consider the possible contribution to extreme insomnia of other causes of

   Nothing in this argument is saying that anything caused something else, so we wouldn't be able to weaken the argument by bringing up alternate causes. This argument is only talking about people who are / aren't a certain thing, or who do / don't do a certain thing.

   7%
3. C

   Correct44% picked this

   It relies on evidence that does not indicate the frequency of extreme insomnia among people who drink

   Why this is right

   This is pointing out the fact that the statistic the author cites is useless to the argument she's trying to make. If we're saying, Tom drinks coffee. Thus he's probably an insomniac. We need to know that Most coffee drinkers are insomniacs. In order for us to assess the likelihood that Tom is an extreme insomniac, based on the fact that he drinks a lot of coffee, then we need to know, "What % of big coffee drinkers are extreme insomniacs". (Instead, the author uselessly brought up what % of extreme insomniacs are big coffee drinkers) This answer choice is just complaining that the author didn't provide us with the actual statistic that we'd need to evaluate the conclusion (or that she would need to prove the conclusion). If you want to try a similar problem, try this one.

   Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

   44%
4. D

   Wrong Flaw: not Part v. Whole30% picked this

   It draws an inference about one specific individual from evidence that describes only the characteristics of

   If a flaw answer choice says the author inferred X from evidence that Y, we would ask ourselves if Y matches the Evidence and if X matches the Conclusion (or some assumption en route to the conclusion). Was the conclusion "an inference about one specific individual"? Sure, it was about Tom. Was the evidence describing only the characteristics of a class of individuals? No, not quite. First of all, there are two premises, and one of them is just about Tom (he drinks a lot of coffee). That would already make us doubt this answer. It's also tough to say that "90% of extreme insomniacs consume a large amount of coffee" is describing the characteristics of a class of individuals. It's describing a characteristic about 90% of a class of individuals. One final issue is that it's not inherently objectionable to draw an inference about a specific individual from evidence that describes the characteristics of a class. i.e., if the argument had been "All big coffee drinkers are insomniacs. Tom drinks coffee. Thus, Tom is an insomniac", that would be an airtight argument and this answer choice would still be applicable.

   30%
5. E

   Too Strong6% picked this

   It presumes without warrant that drinking coffee always

   Too Strong: always Out of Scope: causal Nothing about this argument is causal, so the author didn't need to make any assumption about anything causing other stuff. She certainly didn't need to make any extreme assumption that drinking coffee always causes insomnia.

   6%