PrepTest 131

[lcid:3623] Prep Test 131 LSAT — Reading Comp — S4 Reading comp

Passage

Questions 1-8 Passage A  .        Recent studies have shown that sophisticated  . computer models of the oceans and atmosphere Remaining source text redacted.
Passage walkthrough
Passage Summary

Topic: Science


Passage A

Paragraph 1

  • Paragraph note
    • Computer models - Accurate but variable
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • Climate models (oceans/atmospheres)
    • Author - Remarkable accuracy
    • Many variables, wide range of values

Paragraph 2

  • Paragraph note
    • Problem
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • To solve for variables, brute force calculations
    • Example - 5 values, 9 variables = 2m calculations
    • Problem - Current individual computers can’t handle

Paragraph 3

  • Paragraph note
    • Solution - Connected computers; Requirement
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • Private computers stronger, can be connected via internet
    • Solution - Divide calculations up between computers
    • Requirement - Get public interested so they sign up

Passage B

Paragraph 1

  • Paragraph note
    • New discovery
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • Researchers - Many problems in many areas are “parallel”
    • Parallel - Solved by working simultaneously
    • Similar characteristics - Lots of similar elements with simple rules that work together

Paragraph 2

  • Paragraph note
    • Example - Ants
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • Individual ant - Follows simple rules
    • Colony of ants - Complex behavior

Paragraph 3

  • Paragraph note
    • Shift in computer
  • Views, minor Meta-Structures, points of intersection, and the author's attitude
    • Shift - Sequential (one calc at a time) → Parallel (thousands of computers at same time)
    • Problems = Parallel, makes sense to use same type of computer
    • Perform BEST
    • Old - Speed limits

Main Points:

Passage A - Adopting the use of many computers solving problems simultaneously will better allow for the exploration of complex systems such as ocean and atmosphere modes.

Passage B - A paradigm shift in computing is moving us away from sequential computing to parallel computing, which will be best able to tackle the problems that are inherently parallel.

Key Lines?

Passage A:

  • Lines 19-21 - The problem is stated, and the current approach is implied
  • Lines 22-28 - The solution/new approach
  • Lines 30-32 - A requirement for the new approach to work

Passage B:

  • Lines 33-37 - Discovery
  • Lines 37-42 - Common elements of problems
  • Lines 53-56 - The old and new approaches are noted
  • Line 63 - Superlative

Meta-Structure? Relationship Between Passages?

These two passages don’t use exactly the same language, but they both largely overlap in talking about a shift in computing away from sequential/individual computing systems and towards connected/simultaneous ones for solving problems with complex variables that run in parallel. They use different examples, but they both arrive at the same conclusion. As such, these passages largely align and we should take that into account as we tackle the questions.

Old Approach/New Approach (Both) - Both passages, at their core, are about a new approach to computing that can address a set of problems that the old paradigm can’t (see the Problem/Solution discussion below). That old approach is simultaneous or sequential computing, where the necessary calculations are done one-at-a-time, and in order. The new approach is called “simultaneous” or “parallel” computing, and it involves connecting a lot of computers that each run some of those calculations in parallel, allowing for many calculations to be done at once. Both say that this approach is helping to perform complex calculations/solve computing problems. When a passage has an extended Old Approach/New Approach Meta-Structure, the Author’s opinion on the new approach is generally the main point. They both have similar opinions on that new approach, leading to the main points as we stated them above.

Problem/Solution (Both) - This is an offshoot of the Old Approach/New Approach Meta-Structure, where the new approach is an attempt to solve a problem with the old one. The old approach - sequential computing - couldn’t handle the number of calculations necessary to tackle many problems, and so the new approach - parallel/simultaneous computing - was developed to meet the needs of these problems. The solutions here line up with the New Approach from that Meta-Structure, reinforcing our view of the main point while expanding the language that we should look for in the answer choices.

Examples (Passage A) - Passage A brings up a type of “thing” that parallel computing can help to solve - computer models of oceans and the atmosphere, building to large-scale climate trends. This shows up in Paragraph 1, but it isn’t discussed at length after that, so this is a limited Meta-Structure and probably will serve as the basis for just a question or two.

Examples (Passage B) - Passage B uses ants foraging for food as an example of the type of complex system that can form when a bunch of simple elements work together - the characteristics of the problems that are solved well by parallel computing. Note that this isn’t an example of the type of problem that parallel computing can solve, but rather a highly complex system that emerges from simple parts.

Last Thoughts?

While both passages use examples, they use them for different purposes. Passage A brings up some problems that parallel computing can help to solve - running computer models of certain natural systems. Passage B, on the other hand, uses an example to highlight the type of complex system that can emerge from simple interactions, but it’s not necessarily something that a parallel computer would “solve” - it’s not even clear what it would mean to “solve” ant foraging behavior. Let’s keep these different roles in mind for any Argument Structure questions that show up.

Question prompt

It can be inferred 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

Strategy Overview

Review what we said about the relationship between the two passages, and use that to anticipate what they would agree on concerning computer systems

Answer Anticipation

These two passages don’t use exactly the same language, but they both largely overlap in talking about a shift in computing away from sequential/individual computing systems and towards connected/simultaneous ones for solving problems with complex variables that run in parallel.Passage A argues that computers are currently “completely inadequate” for the task of brute forcing the calculations that are needed to solve for the number of variables involved in some complex systems (Lines 19-21). However, as computers get stronger and the Internet allows them to be connected, they can solve these problems by running simultaneously (Lines 22-26).Similarly, Passage B argues that a “computing model that resembles” parallel problems will “perform best” (Lines 61-63).Big picture, then, both passages argue that parallel/simultaneous computing is best able to handle problems that involve parallel features/a lot of variables that need to be calculated simultaneously. Let’s use that to guide us through the answers.

Answer choices

  1. A
    Massive, parallel computing systems Remaining source text redacted.
    Why choice A is not credited

    (A) (Lines 12-15) Passage A says that there is “no alternative” to brute force for these problems, so this answer is wrong in saying that parallel computers don’t have to resort to that method.

  2. B
    Computer models are not Remaining source text redacted.
    Why choice B is not credited

    (B) (Lines 1-4) Neither passage claims that parallel computing can’t simulate the behavior of insects. Passage A claims that computer models can simulate climate trends with remarkable accuracy, and those trends could very well be as complex as biological populations such as insect colonies. And Passage B argues that ant colonies are the type of highly complex system that can be “effectively solved” by parallel computing.

  3. C
    Parallel computing systems that Remaining source text redacted.
    Why choice C is not credited

    (C) (Lines 29-30) The Author of Passage A claims that such systems “have already been successful.” The Author of Passage B also isn’t skeptical of these systems developing.

  4. D
    Currently available computers are Remaining source text redacted.
    Why choice D is not credited

    (D) (Lines 16-21) The Author of Passage A says that current computers are completely inadequate for a task that involves “2 million calculator-intensive simulation runs,” but she might believe that current computers can run simulations with fewer variables - say, a simulation of a coin flip that’s done over and over again.

  5. E
    Parallel computing systems employing Remaining source text redacted.
    Why choice E matches the stem

    (E) (Lines 19-21; Lines 61-63) The Author of Passage A discusses the problem with using current individual computers for running climate models, and she puts forward parallel computing as a means of solving this problem. The Author of Passage B concludes that a computing model that “resembles the inherently parallel problem it is trying to solve will perform best,” and we know that climate trends involve such parallel variables. As such, the Authors would agree with this answer - and, in fact, it’s essentially the main point of both passages.

What this tests

Discussion

  • Ans Choice B 2 replies

    Started by ankita96

  • help 2 replies

    Started by Lucas

View all discussions Start a discussion