LSAT 117 | Section 2 | Logical Reasoning: Q21

LR Question 21 Explanation

QUESTION TEXT: It is highly likely that Claudette …

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Claudette is probably a classical pianist.

REASONING:

• Most classical pianists recognize many of Schumann’s works.
• Most people who are not classical pianists do not recognize many of her works.
• Claudette recognizes many of Schumann’s works.

ANALYSIS: The premises tell us that most non-classical pianists don’t recognize Schumann’s works.

But “most do not” still leaves open the possibility that a large number do.

For example:

• 90% of non-classical pianists do not recognize her works.
• 10% do.
• If there are millions of non-classical pianists and only thousands of classical pianists, most people who recognize her works could still be non-classical pianists.

So the flaw is that the author never considers whether many non-classical pianists also recognize Clara Schumann’s works.

___________

1. Her familiarity with other composers is irrelevant.
2. The argument never relies on the assumption that people who have not heard of Clara Schumann fail to recognize her works. The final sentence (“many people haven’t even heard of her”) is just extra support for the claim that many non-classical pianists do not recognize her works.
3. Whether classical pianists play other instruments is irrelevant.
4. Nothing depends on ambiguity in the word “classical.”
5. CORRECT. If this possibility were true, recognizing her works wouldn’t make it highly likely that Claudette is a classical pianist.
    
   This is a classic base-rate flaw. The author assumes that because a trait is common among classical pianists and uncommon among non-classical pianists, someone with the trait is probably a classical pianist, without considering the relative sizes of the groups.