PrepTest 144
[lcid:3672] Prep Test 144 LSAT — Reading Comp — S1
Reading comp
Passage
. Passage A . Karl Popper's main contribution to the philosophy . of science concerns the power of negative evidence.
Remaining source text redacted.
Passage walkthrough
Passage SummaryTopic: Science
Passage A
Paragraph 1
Paragraph 1
Passage A - Popper's philosophy of science doesn't reflect the reality scientists face, especially with respect to the certainty with which negative evidence can disprove theories.
Passage B - When predicting the orbit of Uranus, scientists were correct in predicting a new planet, but in a similar situation with Mercury, it was actually Newton's laws that were shown to be incorrect.
Key Lines:
Passage A:
Lines 3-5 - An example makes a distinction much clearer
Lines 6-10 - A view is clarified and the Author calls it exaggerated ("hyperbolic")
Lines 17-19 - The Author criticizes the opposing view
Lines 30-32 - The Author clarifies her view, showing a shared viewpoint and an opposed viewpoint with the opposing point
Passage B:
Lines 41-44 - Alternative possibilities are discussed
Lines 48-51 - One possibility is shown to be correct
Lines 53-54 - A similar situation is raised
Lines 58-64 - A different possibility is shown to be correct in this example, with implications for the first
Meta-Structure - Relationship Between Passages:
Rebuttal (Passage A) - The Author of Passage A clearly thinks that Popper's philosophical contribution isn't 100% correct. However, she does clarify this at the end. Popper claims that positive evidence is inconclusive, but negative evidence is definitive in disproving a claim. The Author agrees that positive evidence is inconclusive (though she disagrees with Popper's view that it lacks all value), but she disagrees that negative evidence is always conclusive.
Comparisons (Passage B) - Passage B brings up two similar situations—planets are discovered, their orbits are predicted, and those predictions are wrong. However, the outcome of these situations is different. In the Uranus situation, it ended up being an auxiliary assumption (no other planets in the area) that was wrong. In the Mercury situation, it ended up being Newton's theories that were wrong.
Neutral Author (Passage B) - The Author of Passage B doesn't really take any sides or show any opinion. Rather, he focuses on presenting the details of two separate situations.
How do these passages relate? In a complicated manner! The first passage discusses an approach to scientific inquiry that revolves around positive and negative evidence. How does this apply to the two situations in Passage B? Well, in the Uranus case, the scientists used what they knew to predict an orbit, and that orbit turned out to be wrong. In other words, they made a prediction, and the evidence proved that prediction wrong—negative evidence!
In the Mercury example, they predicted an orbit that turned out to be wrong, so that's more negative evidence. They also then made a prediction that, similar to the Uranus situation, there would be another planet, but they didn't find one—also negative evidence!
(This was a lot of analysis, and we almost certainly wouldn't have walked through all of this ahead of heading to the questions. It's here to help you wrap your head around the passages!)
Also important to note is that the Author of Passage A talks about "auxiliary" assumptions, and Passage B brings these up as a possible place for a prediction made by a theory to go wrong. That overlap aligns the approach in Passage B with that of the Author over Popper.
Last Thoughts:
This comparative set is rough. It's hard to understand, abstract, and definitely outside of most people's area of expertise. So what can you do to make it easier? Rely on that example in Passage A, Paragraph 1. If we can understand what positive and negative evidence is, we should be able to muddle through the detail questions. And as for the Authors' viewpoints, Passage A has some clear statements of opinion, and Passage B lacks a particularly present author.
Passage A
Paragraph 1
- Paragraph note
- A philosopher is introduced, and his theory is explained in depth, focusing on a distinction
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Popper - Theory of negative evidence (vs positive evidence)
- Example - "All swans are white"
- Positive evidence - white swans (can't prove all are white); Popper says no value
- Negative evidence - black swan (one proves idea is wrong); Popper says disproves
- Author - Popper's view "hyperbolic"
- Popper - Negative evidence is core of science (scientific theory → makes predictions testable with negative evidence)
- Paragraph note
- The Author rebuts Popper's argument to some degree
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Author - Popper's view doesn't reflect scientific reality
- False prediction, premise of theory is wrong
- But which one? All theories have "auxiliary" premises from other theories and the real world (e.g., instruments work)
- Author - Popper is right to say positive evidence isn't conclusive; wrong to say negative evidence is
Paragraph 1
- Paragraph note
- A scientific situation is walked through
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Uranus orbit predictions were off, relied on Newton's laws, and auxiliary assumptions (including no other planets were nearby)
- Predictions wrong, so a premise must have been wrong
- Scientists tested other planets around, found that was the mistake
- Paragraph note
- A similar scientific situation is walked through
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Mercury orbit predictions were off, scientists predicted another planet (like with Uranus)
- No planet found, Einstein's new laws matched up with reality, so scientists rejected Newton's theory
Passage A - Popper's philosophy of science doesn't reflect the reality scientists face, especially with respect to the certainty with which negative evidence can disprove theories.
Passage B - When predicting the orbit of Uranus, scientists were correct in predicting a new planet, but in a similar situation with Mercury, it was actually Newton's laws that were shown to be incorrect.
Key Lines:
Passage A:
Lines 3-5 - An example makes a distinction much clearer
Lines 6-10 - A view is clarified and the Author calls it exaggerated ("hyperbolic")
Lines 17-19 - The Author criticizes the opposing view
Lines 30-32 - The Author clarifies her view, showing a shared viewpoint and an opposed viewpoint with the opposing point
Passage B:
Lines 41-44 - Alternative possibilities are discussed
Lines 48-51 - One possibility is shown to be correct
Lines 53-54 - A similar situation is raised
Lines 58-64 - A different possibility is shown to be correct in this example, with implications for the first
Meta-Structure - Relationship Between Passages:
Rebuttal (Passage A) - The Author of Passage A clearly thinks that Popper's philosophical contribution isn't 100% correct. However, she does clarify this at the end. Popper claims that positive evidence is inconclusive, but negative evidence is definitive in disproving a claim. The Author agrees that positive evidence is inconclusive (though she disagrees with Popper's view that it lacks all value), but she disagrees that negative evidence is always conclusive.
Comparisons (Passage B) - Passage B brings up two similar situations—planets are discovered, their orbits are predicted, and those predictions are wrong. However, the outcome of these situations is different. In the Uranus situation, it ended up being an auxiliary assumption (no other planets in the area) that was wrong. In the Mercury situation, it ended up being Newton's theories that were wrong.
Neutral Author (Passage B) - The Author of Passage B doesn't really take any sides or show any opinion. Rather, he focuses on presenting the details of two separate situations.
How do these passages relate? In a complicated manner! The first passage discusses an approach to scientific inquiry that revolves around positive and negative evidence. How does this apply to the two situations in Passage B? Well, in the Uranus case, the scientists used what they knew to predict an orbit, and that orbit turned out to be wrong. In other words, they made a prediction, and the evidence proved that prediction wrong—negative evidence!
In the Mercury example, they predicted an orbit that turned out to be wrong, so that's more negative evidence. They also then made a prediction that, similar to the Uranus situation, there would be another planet, but they didn't find one—also negative evidence!
(This was a lot of analysis, and we almost certainly wouldn't have walked through all of this ahead of heading to the questions. It's here to help you wrap your head around the passages!)
Also important to note is that the Author of Passage A talks about "auxiliary" assumptions, and Passage B brings these up as a possible place for a prediction made by a theory to go wrong. That overlap aligns the approach in Passage B with that of the Author over Popper.
Last Thoughts:
This comparative set is rough. It's hard to understand, abstract, and definitely outside of most people's area of expertise. So what can you do to make it easier? Rely on that example in Passage A, Paragraph 1. If we can understand what positive and negative evidence is, we should be able to muddle through the detail questions. And as for the Authors' viewpoints, Passage A has some clear statements of opinion, and Passage B lacks a particularly present author.
Question prompt
Which one of the
Remaining source text redacted.
Why the credited answer is right
Credited answer: E
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
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AGalileo proposed that ocean Remaining source text redacted.
Why choice A is not credited
Incorrect. In this situation, a theory made a false prediction, but "fixing" it so that the theory was still correct didn't lead to a new discovery. -
BBy observing "variable stars"—stars Remaining source text redacted.
Why choice B is not credited
Incorrect. This answer features a discovery that settled a debate—it doesn't feature a theory that was wrong. -
CWalter Alvarez postulated that Remaining source text redacted.
Why choice C is not credited
Incorrect. This answer features a theory that lines up with observed events (the extinction of dinosaurs), and then another discovery that also supports the theory. However, Alvarez's theory didn't make an incorrect prediction, and it didn't lead to the discovery of the crater, so this answer is wrong. -
DBernard Brunhes discovered rocks Remaining source text redacted.
Why choice D is not credited
Incorrect. This answer features a discovery that led to a new theory, not a theory with an incorrect prediction leading to a new discovery. -
EWhen a neutron decays Remaining source text redacted.
Why choice E matches the stem
Correct. Question Type:
Parallel Reasoning
Strategy Overview:
Define the role of Neptune in Passage B, then generalize from it to get something we can use to analyze the answer choices
Answer Anticipation/Relevant Lines:
Neptune showed up in Paragraph 1 of Passage B, where the Uranus situation was examined, so let's walk through that.
Uranus was discovered, and scientists tried to predict its orbit based on Newton's laws and assumptions they made about the solar system. However, the orbit was off. From this, they surmised that either Newton's laws were wrong, or one of their assumptions was wrong—including that there were no unknown planets in the area. They decided to assume that there was an unknown planet in the area, and with that found they could predict Uranus's orbit. And also with that, they were able to locate the missing planet precisely—Neptune.
So a theory failed to make a correct prediction, and so either the theory was wrong or another assumption was wrong. And it turned out that the assumption was wrong, leading to the discovery of Neptune. Let's find an answer where, similarly, a theory makes an incorrect prediction, but the theory isn't rejected and instead an assumption is challenged, leading to a new discovery.
Answer Explanation:
This answer features a theory (the law of conservation of energy) that made a prediction that turned out not to be true (the lower level of energy in the product of neutron decay). A scientist tried to reconcile this discrepancy not by throwing out the theory, but by putting forward the existence of something new (a la the scientists assuming there was an unknown planet out there). And this eventually led to that particle being discovered, just as Neptune was discovered. This answer is therefore analogous to the Uranus/Neptune situation, making it the correct answer.
Key Takeaway:
Always focus on the "parts" of something in an analogy. The original situation had Uranus, Neptune, Newton's laws, and an incorrect prediction. That's four individual elements that can be used to analyze the answers—you need enough elements to match up with each of those parts. A lot of these elements are missing a key part, or simply don't have enough parts to fully match up!
What this tests
Discussion
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Choice E 2 replies
Started by DavidW