LR Question 11 Explanation
QUESTION TEXT: Scientist: To study the comparative effectiveness of…
QUESTION TYPE: Flawed Reasoning
CONCLUSION: Athlete’s foot cured ➞ Received medication M
REASONING: Athlete’s foot cured ➞ Received medication M
ANALYSIS: The reporter’s evidence showed that medication M is a necessary condition for being cured.
The reporter then incorrectly concludes that medication M is a sufficient condition. In technical terms, the reporter has incorrectly negated the premise.
The reporter ignores the possibility that medication M cures some but not all cases of athlete’s foot.
Whenever you see a “flawed reasoning” question that uses conditional logic, it’s virtually certain that the author will mix up sufficient and necessary. You should only give an answer serious consideration if it mentions sufficient and necessary conditions, as the correct answer does here.
___________
- CORRECT. This says that the reporter mixed up sufficient and necessary conditions. That is the flaw. We know medication M is necessary for a cure, but that doesn’t mean it’s sufficient.
- The reporter said “anyone in the study”. She wasn’t talking about the population as a whole.
- Same as B. The reporter was only talking about those in the study. She wasn’t talking about the whole population.
- The scientist already eliminate this possibility. They said that medication M was a necessary condition for a cure, and the reporter didn’t say otherwise.
- This answer refers to the population at large. The reporter was only talking about the study.
The reporter didn’t say that in the whole world there’s no subgroup that will only be cured if they don’t take the medicine.
Recap: The question begins with “Scientist: To study the comparative effectiveness”. It is a Flawed Reasoning question. To practice more Flawed Reasoning questions, have a look at the LSAT Questions by Type page.
More Resources for Flaw Questions
- Flaw drills: Use these to practice making examples of abstract flaws.
- Intro Course lesson: This intro course lesson covers Flaw questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers flaw questions.
Hi. I was struggling between A and D. Although I understand why A is correct, I don’t really know why D is not right. The consideration I have is that there is no control group in this study, the study results are only about the two groups each given M and N. So it is possible that no medicine could also cure the athlete’s foot.
Since the question asks about what the reporter did wrong with his reasoning and he didn’t respond to the “ no control group” error, so D is not really addressed by him and can’t be counted as a flaw. Am I doing the right thinking process?
Please let me know you thoughts on it… Thanks
First, it’s important to ask, is the reporter really making the flaw described in (D)? i.e. Does the reporter universalize the results of the study to say that athletes foot in general (that is, all instances of athlete’s foot, even those outside the study) cannot be cured unless one or both of these medications is taken?
(D) assigns too broad a claim to the reporter. The reporter is just talking about the individuals “in the study”.
I am having great trouble with this question (Q11 from PrepTest 62, Sec 2)
The problem I have is that the Scnientist’s conclusion says, ‘The only people whose athlete’s foot was cured had been given medication M’
Because of the ‘only’ I concluded that ‘cured foot’ was the necessary term. So, I did my diagram as follows:
If given M >> Cured foot.
However, wherever I read about this question, it tells me I should have translated it as:
If cured foot>>then given M
Please help me understand this.
“The only” is different from “only”. “The only” is a sufficient indicator.
So it’s saying: Cure –> Medicine M
“The only” is tricky for a lot of people. Memorize that it’s sufficient, and play around with it yourself by making some sentences to see how it works and how it’s different from “only”.
Thank you.