Logical Reasoning Weaknesses

Question 1

1 Flaw in the Reasoning Questions

Question 2

Flaw Question: Family Type, and Definition

Answer 2

Family #1: Prove

Definition: Question stem is asking you to find choose the answer choice that best describes the inherent flaw in the author’s arg. in the stimulus.

Question 3

How to spot a Flaw Question by its language:

• “_________ in the reasoning”
• “____________ to criticism”
• “____________ technique”
• “______________ reasoning”

Answer 3

flaw; vulnerable; questionable; fallacious

Question 4

What type of Reasoning Structures do Flaw questions often use (3)

Answer 4

Comparative Reasoning (71%)

Causal Reasoning (28%)

Conditional Reasoning (23%)

Question 5

How do you know what the correct answer looks like?

Answer 5

Should accurately describe flaw in general terms.

(Watch out for subject-matter answer choices. AC’s typically shouldn’t be talking about the subject matter in the stimulus.)

Question 6

(Wrong) Trap Answer Choices (7)

Answer 6

Out of Scope:

• AC describes something that has nothing to do with the flaw in the stimulus.

Irrelevant Relationship:

• Wrong because of logic; introduce a (conditional) relationship that doesn’t reflect the error in the stimulus.

Too Strong:

• Presents an idea that is stronger than what was assumed in the arg.

Too Weak:

• usually in questions with precursor: “fail to consider”
• answer choices that aren’t strong enough to impact the argument. Does the weakness present an argument that is forceful enough to undermine the arg.

Not a Flaw:

• AC correctly describes something that happened in the stimulus, but it’s not a flaw.

Wrong Flaw:

• AC accurately describes a flaw, just not the one in the stimulus.

Strengthens:

• Does the opposite of what the question stem is asking you to do.

Question 7

2 Assumption (Necessary) Questions

Question 8

Necessary Assumption: Family Type, and Definition

Answer 8

Family #2: Help

Definition: Question stem is asking you to find the statement from which the rest of the argument springs.

The argument cannot exist without this statement.

Question 9

How to Spot of a Necessary Assumption Question by its Language:

• “requires”
• ” __________ on”
• “must”
• “________ if”
• “_________ on”
• “the argument ____________ that”

Btw, for question stems that don’t have any language indicating it’s a necessary assumption question, i.e. “The argument above presumes which one of the following?”, treat it as a default assumption question.

Answer 9

depends; only; relies; presumes

Question 10

Steps to Solving a Necessary Assumption Question (5)

Answer 10

1) Conclusion

• Find the conclusion of the arg.

2) Evidence

• Find the the evidence supporting the conclusion

3) Evaluate

• Evaluate the reasoning of the arg. Find the gap between the premises and conclusion

4) Anticipate

• Anticipate answer choice w/ a Prephrase.

5) Answer Choice

• Hold up Prephrase to answer choices and find best answer choice

Question 11

What are the two types of Assumptions?

Answer 11

Linking Assumptions
Defender Assumptions

Question 12

Linking Assumptions

Answer 12

Assumptions that oftentimes deal with conditional reasoning.

Assumptions that find the missing link between the premises and conclusion.

Your focus in these questions is connecting terms that aren’t already connected, and that means looking at conditional connections that were already established.

(Don’t get sidetracked by statements that don’t ultimately lead anywhere).

Question 13

Defender Assumptions

Answer 13

Assumptions that protect the current relationship in the argument from being destroyed.

The point of defender assumptions is to essentially bat-away ideas that could devastate or weaken the argument.

This means you need to find the ideas that could weaken the argument and assume the opposite (pretty much the same thing as assumption negation).

IF YOU KNOW HOW TO POKE HOLES IN THE ARGUMENT, THEN YOU KNOW HOW (BEST) TO DEFEND IT.

Question 14

(Wrong) Trap Answer Choices (5)

Answer 14

Out of Scope:

• Answer choices that are irrelevant to the argument

Premise Support:

• Answer choices that support the premise and not the arg.’s reasoning.

Too Strong:

• Answer choices that introduce ideas stronger than what’s assumed in the arg.

Weaken:

• Answer choices that destroy the relationship between premises and conclusion.

Negation / Reversal:

• Answer choices that present mistaken reversals, and mistaken negation.

(Also extraneous answer choices)

Question 15

What Reasoning Structures will you most often use in Assumption Questions?

Answer 15

Linking Assumption…

• you’ll probably use conditional reasoning. You’ll evaluate the conditional reasoning in the conclusion and premises and find the gap between the two using a conditional relationship.

Defender Assumption…

• you will try to find what the argument hasn’t considered that could weaken it’s argument, and ASSUME the opposite.
  (AGAIN, IF YOU KNOW HOW TO POKE HOLES IN THE ARG., YOU KNOW HOW TO DEFEND IT.)

Question 16

3 Strengthen Questions

Question 17

Strengthen: Family Type and Definition

Answer 17

Family #2: Help

Definition: Question stem is asking you to find the answer choice that most supports the argument; what makes the argument better.

Question 18

How to Spot a Strengthen Question by its Language:

• “Which one of the following ** _________ strengthens** the argument above?”
• “____________ supports”
• “____________ justifies”
• We’re looking for the answer choice that would _________ impact the argument so you’re going to see the word ___________ alot in Strengthen question stems.
• “Each of the following, if true, strengthens the reasoning above __________…”
• With a Strengthen _________ question, remember, 4 answer choices make the argument ____________, so the 1 right answer choice either __________ or does ____________ and that’s what we’re looking for.

Answer 18

most; most; most; most; most; EXCEPT; EXCEPT (X); better; weakens; nothing

Question 19

Steps to Solving Strengthen Question (5)

Answer 19

1) Identify Conclusion

2) Identify Evidence Supporting Conclusion

3) Evaluate the argument

• in your evaluation, recognize that there’s a gap between the conclusion and premises, such that the conclusion is not supported by the available evidence (that’s why we’re trying to help the arg.).
• Using reasoning structures (comparative, causal, and conditional), figure out what the gap is and how to link the conclusion and premises.

4) Anticipate an answer choice w/ a Prephrase

5) Choose answer choice.

Question 20

Reasoning Structures Used in Strengthen Questions (most often to least often).

Answer 20

Comparative Reasoning (most often)

• comparative reasoning could come about in two ways: comparing two things within the same period of time, or comparing one thing into two different instances of time.
• look for language like, “more effective than…”

Causal Reasoning (next most frequent reasoning structure)

Conditional Reasoning (least frequent reasoning structure)

Question 21

(Wrong) Trap Answer Choices

Answer 21

Out of Scope

• answer choice says something that has nothing to do with the argument.

Weakens

• answer choice contradicts / goes against argument

Irrelevant Relationship

• wrong because of logic; introducing relationship between variables that ultimately isn’t relevant to arg.

Premise Support

• answer choice supports premise, instead of supporting whole argument’s reasoning.
• we’ve already assumed the the truth of the premises, so that doesn’t help.

Too Weak

• answer choice uses terms/language that makes it too weak to strengthen the argument.