PrepTest 129

[lcid:3615] Prep Test 129 LSAT — Reading Comp — S4 Reading comp

Passage

Questions 20-27  .        Fractal geometry is a mathematical theory devoted  . to the study of complex shapes called fractals. Remaining source text redacted.
Passage walkthrough
Passage Summary

Topic: Science


Paragraph 1

  • Paragraph note
    • Fractals explained (self-similar — each part looks like the whole) and Koch curve example ( _^_, each segment also looks like _^_ )
  • Views, minor Meta-Structures, and the author's attitude
    • Definition of "self-similarity": A shape where each little part looks like the whole shape (second sentence)
    • Example of an important fractal that exhibits self-similarity, according to the author:
      • The Koch curve, which is a straight line with a bump in the middle, but each smaller line has bump, repeated ad infinitum (third through last sentence)
    • Author's attitude: "significant" (third sentence); "provides some insight" (third sentence)

Paragraph 2

  • Paragraph note
    • Use of computers in fractal geometry (not limited by what can be drawn/displayed, so can create more complex fractals)
  • Views, minor Meta-Structures, and the author's attitude
    • Author's view:
      • Computers illustrate why many people are interested in fractals, given that programming simple steps can create very complex patterns (last sentence)
    • Comparison, according to the author:
      • Creating an image of the Koch curve without a computer will be limited by how small we can draw or display each line segment; however, using computers to make Koch curves doesn't have such a limit (third and fourth sentences)
    • Author's attitude: "dramatically illustrates a major attraction" (last sentence); "simple processes" (last sentence); "incredibly complex patterns" (last sentence)

Paragraph 3

  • Paragraph note
    • Debate over usefulness between enthusiasts (a new form of math that can describe complex natural forms) and skeptics (hasn't yet created theorems/proofs)
  • Views, minor Meta-Structures, and the author's attitude
    • Public's view:
      • Captivated by complex images (first sentence)
    • Fractal enthusiasts' view:
      • Fraticals represent a new mathematical system that can describe natural/mathematical forms (first and second sentences)
    • Comparisons, according to the fractal enthusiasts:
      • Fractal geometry will become as important as calculus (second sentence)
      • Fractal will allow mathematicians to describe the shape of a cloud as easily as architects can describe a house with traditional geometry (second sentence)
    • Fractal skeptics' view:
      • Fractal enthusiasts are too focused on images and need to show that fractal geometry can prove theorems (third through last sentences)
    • Comparison, according to the fractal skeptics:
      • Pre-fractal math has proven many theorems about fractals, but fractal geometry has only proven a few theorems that couldn't have been proven without fractals (fourth sentence) and only a few have been demonstrated
    • Author's attitude: "captivated" (first sentence); "astonishing" (first sentence)

Main Point: The ability of fractal geometry to generate complex patterns from simple processes has captivated the public and some practitioners, but others are skeptical that it can be used to prove theorems and thus have a lasting role in math.

Meta-Structure?

Describing a Debate: Even though the author doesn't bring up the debate until the last paragraph, this passage best fits the Describing a Debate Meta-Structure.* In such a passage, the author describes two sides of a debate without taking a side or attempting to reconcile the two sides. (If the author takes a side or attempts to resolve the debate, the passage is better understood as a "Resolving a Debate" passage.) In this passage, the author uses the first two paragraphs to explain the passage's subject matter (fractal geometry) before finally presenting the debate over that subject matter's usefulness. The author doesn't take sides in the debate beyond saying that the subject matter can produce some wild images.

In passages that utilize a Describing a Debate Meta-Structure, the main point generally describes both sides of the debate (or the assertion that there is a debate). We constructed our anticipated main point around both sides of the debate, while also including the public's fractal fascination for good measure.

*That said, we could call this an Old Approach/New Approach passage, with pre-fractal geometry as the old approach and fractal geometry as the new approach. That said, pre-fractal geometry doesn't play a huge factor in this passage, so we think this passage is better understood as a Describing a Debate passage.

Example: The passage dedicates a fair amount of real estate to the Koch curve example, making this example the most prominent minor Meta-Structure in the passage. This part of the passage describes the process by which that curve is generated and illustrates certain features of fractals (namely, self-similarity). The Koch curve is also discussed in the context of computer generation. This example is meant to explain to the reader what fractals are, and it's ancillary to the debate raised in the third paragraph, so it's more likely to show up as the topic for a few Minor Point, Application, or Argument Structure questions.

One more note about this example: the description of the Koch curve process is really hard to follow if you're not drawing it out. That doesn't mean you need to draw it out, as it's unlikely that there will be a lot of questions on it. But if you have the time, running through the relevant steps one or two times can be helpful for the questions that do involve the specifics!

Last Thoughts?

This passage's main point can trip up some test-takers. How come our anticipated main point only summarizes the third paragraph? Aren't main points supposed to be comprehensive and summarize the entire passage?

These are good questions and valid concerns! But it's important to remember that in Reading Comp, arguments are far more important to the passage than details. The first two paragraphs only include details. They describe what fractals are and how people generate them using computers. These details essentially provide background information on the passage's subject matter.

We don't get arguments until the third paragraph. Each side presents their argument on the utility of fractals. "Fractals are useful because they'll help mathematicians describe natural shapes easily." "Fractals are not yet useful because they don't support a system of theorems and proofs." These arguments feature details (the evidence both sides use), but they also feature conclusions — evidence-backed opinions that each side has about fractals. Much as we understand arguments through the conclusion in LR, we’ll understand passages through their conclusions in RC. These conclusions help identify what's really important in the passage. We'll use those conclusions to define the passage's Meta-Structure and main point.

Question prompt

Each of the following Remaining source text redacted.
Why the credited answer is right

Credited answer: A

The notes below walk through why it fits the stem and how to eliminate the rest.

Question Type

Science

Strategy Overview

Refer to notes or what you highlighted/underline to locate where the passage discusses the Koch curve, then head to the answers and refer to the relevant part of the passage as needed to eliminate answer choices that must be true

Answer Anticipation

For these Bizarro Must Be True questions, the incorrect answers will all be supported by the passage. The correct answer will either present a topic not discussed by the passage or assert a claim contradicted by the passage. Therefore, it can be difficult to predict what the correct answer will say. However, when the question stem provides some guidance as to where the textual support is located in the passage, we can predict what the incorrect answers will say. Taking a little bit of time to make this prediction can allow us to eliminate the incorrect answers very quickly.In this case, we're asked what's true of the Koch curve. Based on our notes, we know most of the information on the Koch curve comes from the first paragraph. Reviewing that paragraph, we'll be reminded that the Koch curve is a fractal and that it displays self-similarity (P1, S3). The description of how to generate the Koch curve is described as a simple process (P2, S4), but without having time to sit down and really think it through, it can be tough to internalize and really see what's going on there. So, let's take it step-by-step. We start with a line (P1, S4), erase the middle third, and replace that with a triangular bump (P1, S5). All the new lines are the same size (P1, S6). We then erase the middle third of each of these sections and do the same (P1, S7). If you drew something out, that's not necessarily a bad move!The second paragraph says that this process can have infinitely many steps, but there are limits to drawing and displaying each little bump (P2, S3).With all this in mind, let's head to the answers. We'll eliminate each answer choice that's consistent with what we reviewed until we find one that's not supported by the passage.

Answer choices

  1. A
    The total number of Remaining source text redacted.
    Why choice A matches the stem

    (A) Is this consistent with what we reviewed about the Koch curve?

    No. The process involves erasing the "middle third of the line" and replacing it with two line segments (P1, S5). No matter how long the initial line was, you're still erasing one-third of it and replacing that section with two new lines that form a single protrusion. So, the length of the line doesn't determine how many protrusions there are, but rather how many steps you've gone through. This answer, therefore, doesn't correctly describe the process, so it's the correct answer. We can justifiably select (A) and advance immediately to the next question.

  2. B
    The line segments at Remaining source text redacted.
    Why choice B is not credited

    (B) Is this consistent with what we reviewed about the Koch curve?

    Yes! The process involves erasing the middle third of the line and replacing it with "two line segments, each as long as the removed piece" (P1, S5). So, each line segment is ? of the length of the removed line segment, which is ? of the length of the previously removed line segment, and so on and so on. The line segments keep getting smaller, (? smaller, to be precise), so we can eliminate this answer.

  3. C
    Theoretically, as the Koch Remaining source text redacted.
    Why choice C is not credited

    (C) Is this consistent with what we reviewed about the Koch curve?

    Yes! As we just noted in (B), the line segments get shorter with each step (P1, S5). And the passage also says that, in theory, the Koch curve is the result of infinitely many steps (P2, S3). Ergo, the line segments would theoretically get infinitely small, so we can eliminate this answer.

  4. D
    At every stage of Remaining source text redacted.
    Why choice D is not credited

    (D) Is this consistent with what we reviewed about the Koch curve?

    Yes! As we reviewed, each part of the Koch curve comprises "four connected segments of equal length" (P1, S6). So, all the pieces are the same size at each stage/part. We can eliminate this answer.

  5. E
    The length of the Remaining source text redacted.
    Why choice E is not credited

    (E) Is this consistent with what we reviewed about the Koch curve?

    Yes! At each step of the process in generating the Koch curve, you erase ? of the length of each line (P1, S5). Since the amount erased is a proportion of the whole, the length of the starting line segments is relevant to determining how big each successive step's line segments are, so this answer can be eliminated. (Contrast this with (A), which discussed the number of protrusions, not the length of the line segments. Since the steps involve a proportion of length but not a counting of protrusions, this answer is supported by the passage while that one isn't.)

What this tests

Discussion