Logical Reasoning Bible
解 题 思 路 整 理
I Primary Objectives:
?. Determine whether the stimulus contains an argument or if it is only a set of
?. If the stimulus contains an argument, identify the conclusion of the argument; If
the stimulus contains a fact set, examine each fact;
?. If the stimulus contains an argument, determine whether the argument is strong or
?. Read closely and know precisely what the author said. Do not generalize;
?. Carefully read and identify the question stem; Do not assume that certain words
are automatically associated with certain question types;
?. Prephrase; After reading the question stem, take a moment to mentally formulate
your answers to the question stem;
?. Always read each of the five answers;
?. Separate the answer choice into contenders and losers; After completing this
process, review the contenders and decide which is the correct one;
?. If all 5 answers appear to be losers, return to the stimulus and reevaluate the
II Basics of Logical Reasoning
Premise Indicators Counter-Premise Indicators Conclusion Indicators
because, since, for, for But, yet however, on the thus, therefore, hence,
example, for the reason that, other hand, admittedly, in consequently, as a result,
in that, given that, as contrast, although, even so, accordingly, clearly,
indicated by, due to, owing though, still, whereas, in must be that, shows that,
to, this can be seen from, spite of, despite, after all conclude that, follows that,
we know this by, for this reason,
besides, in addition, what’s
more, after all
Quantity Indicators Probability Indicators
all, every, most, many, some, several, few, Must, will, always, not always, probably, sole, only, not all, none likely, would, not necessarily, could,
Family #1 Must Be or Prove Family
1. Must Be True Questions
Fact Test The correct answer to a Must Be True
question can always be proven by referring
to the facts stated in the stimulus.
You can often predict the occurrence of
Must Bu True questions because the
stimulus of most Must Be True questions
does not contain a conclusion.
Correct Answer Types ; Paraphrased answers, restating a
portion of the stimulus in different
; Combination answers, resulting
from combining 2 or more
statements in the stimulus.
Incorrect Answer Types ; Could Be True answers;
; Exaggerated answers;
; New Info;
; Shell Game;
; The Opposite answers;
; Reverse answers.
2. Main Point Questions
Many Main Point problems Main Point---Fill in the Incorrect Answer Types:
feature a structure that Blank Questions
a. Answers that are true but places the conclusion either
do not encapsulate the The blank is always at the at the beginning or in the
author’s point; end of the stimulus. There is middle of the stimulus.
a conclusion indicator at the
b. Answers that repeat start of the sentence to help
premises of the argument. you recognized that are
being asked to fill in the
conclusion of the argument.
3. Point at Issue
Incorrect Answers in Point a. Ethical versus Factual Situations;
at Issue Questions
b. Dual Agreement or Dual Disagreement;
c. The View of 1 Speaker is Unknown.
The Agree/Disagree Test The correct answer must produce responses where one
speaker would say “I agree, the statement is correct” and
the other speaker would say “I disagree, the statement is
incorrect”. If those two responses are not produced, then
the answer is incorrect.
4. Method of Reasoning
Method of Reasoning Questions Types The stimulus for a Method of Reasoning question will contain an argument, and the
argument can contain either valid or invalid reasoning.
You must watch for the presence of the premise and conclusion indicators.
Use Fact Test to eliminate answers. If an answer choice describes an event that did not occur in the stimulus, then that answer
Several types of incorrect questions:
; “New” Elements Answers;
; Half Right, Half Wrong;
; Exaggerated Answers;
; Opposite Answers;
; Reverse Answers.
Method of Reasoning—Argument Part Method—AP questions often feature 2
Question conclusions—a main conclusion and
subsidiary conclusion—where the main
conclusion is typically placed in the first or second sentence and the last sentence
contains the subsidiary conclusion.
Trick: the test makers in Method—AP is to
create wrong answers that describe parts of
the argument other than the part named in the question stem.
5. Flaw Questions
Common Errors of Reasoning Explained
a. Uncertain Use of a Term or Concept i. Appeal Fallacies
; Appeal to authority;
; Appeal to Popular Opinion/Appeal
; Appeal to Emotion.
b. Source Argument j. Survey Errors
ad hominem, or attack the person (or ; Survey uses a biased sample; source)
; Survey questions are improperly
; Focusing on the motives of the constructed;
; Respondents to the survey give
; Focusing on the actions of the inaccurate responses.
c. Circular Reasoning k. Exceptional Case/Overgeneralization d. Errors of Conditional Reasoning l. Errors of Compositions and Division
; Mistaken Negation; 以偏概全或以全概偏
; Mistaken Reversal;
; Confuse a necessary condition
for a sufficient condition;
; Confuse a sufficient condition
with a required condition.
If you identify a stimulus with conditional reasoning and are asked a Flaw question, you can quickly scan the answers for the one answer that contains “Sufficient”, “Necessary” or both.
e. Mistaken Cause and Effect m. False Analogy
; Assuming a causal relationship
on the basis of the sequence of
; Assuming a causal relationship
when only a correlation exists;
; Failure to consider an alternate
cause for the effect, or an
alternate cause for both the cause
and the effect;
; Failure to consider that the events
may be reversed.
If you identify a stimulus with causal reasoning and are asked a Flaw question, quickly scan the answers for one that contains “Cause”, “Effect” or both.
f. Straw Man n. False Dilemma
Ignore the actual statements made by the opposing speaker and instead distorts and
refashions the argument.
g. General Lack of Relevant Evidence of o. Errors in the Use of Evidence
; Lack of evidence for a position is
taken to prove that position is false;
; Lack of evidence against a position
is taken to prove that position is
; Some evidence against a position is
taken to prove that position is false;
; Some evidence for a position is
taken to prove that position is true. h. Internal Contradiction p. time shift errors
q. Numbers and Percentages Errors.
Author improperly equates a percentage
with a definite quantity, or when an author
uses quantity info to make a judgment
about the percentage represented by that
6. Parallel Questions
The question stem for any Parallel question reveals whether the stimulus contains valid or
invalid reasoning. If the question stem mentions a flaw, then the reasoning is invalid. If
the question stem does not mention a flaw, then the reasoning is valid. The following elements do a. Topic of the stimulus;
not need to be paralleled:
b. The order of the presentation of the premises and
conclusions in the stimulus.
You must parallel all of a. The Method of Reasoning;
b. The Validity of the Argument;
c. The Conclusion;
d. The Premises.
If all else fails, Create a short statement that summarizes the “action” in
the argument. Then take the abstraction and compare it to
Family #2 Help Family
7. Strengthen Questions
To effectively strengthen 3 Incorrect Answer Traps To strengthen a Cause and arguments Effect relationship
Identify the conclusion; Eliminate any alternate ; Opposite answers;
Personalize the argument; ; Shell game answers;
Show that when the cause Look for weakness or holes occurs, the effect occurs; ; Out of scope
in the argument.
answers. Show that when the cause
does not occur, the effect
does not occur;
Eliminate the possibility
that the stated relationship
Show that the data used to
make the causal statement is
accurate, or eliminate
possible problems with the
8. Justify Questions
Justify Formula The following rules apply:
Premise + Answer Choice = Conclusion a. Any “New” element in the conclusion
will appear in the correct answer;
b. Elements that are common to the
conclusion and at least 1 premise, or to 2
premises, normally do not appear in the
c. Elements that appear in the premises but
not the conclusion normally appear in
9. Assumption Questions
The relationship between the conclusion and the assumption can be described as:
Assumption Conclusion ValidTrue
Supporter/Defender Assumption Model
Supporter Assumption: These assumptions link together new or rogue elements in the stimulus or fill logical gaps in the argument.
Defender Assumption: These assumptions statements that eliminate ideas or assertions
that would undermine the conclusion.
If there is no obvious weakness in the argument and you are faced with an Assumption question, expect to see a Defender answer choice.
Assumption Negation Technique:
a. logically negate the answer choices under consideration;
b. the negated answer choice that attacks the argument will be the correct answer.
3 Quirks of Assumption Question Answer Choice:
a. Watch of answers starting with the phase “at lease one” or “at least some”;
b. Avoid answers that claim an idea was the most important consideration for the author;
c. Watch for the use of “not” or negatives in assumption answer choices.
Assumptions and Conditionality:
a. If conditional statements are linked together in the argument, the correct answer choice for an Assumption question will typically supply a missing link in the chain;
b. If no conditional chains are present and only a conditional conclusion exists, the
correct answer will usually deny scenarios where the sufficient condition occurs and the
necessary does not, or it works as a Defender.
Assumption and Causality: ：解题思路与Strengthen Causality类似；
a. Eliminate any alternate causes;
b. Show that when the cause occurs, the effect occurs;
c. Show that when the cause does not occur, the effect does not occur;
d. Eliminate the possibility that the stated relationship is reversed;
e. Show that the data used to make the causal statement is accurate, or eliminate possible
problems with the data.
10. Paradox Questions
The correct answer will The following types of Note: You must address the allow 2 sides to be factually answers are incorrect: facts of the situation. Many correct. answers will try to lure you
; explain only 1 side with reasonable solutions
of the paradox; that do not quite meet the
stated facts. These answers
; b. Similarities and are incorrect.
Family #3 Hurt Family
11. Weaken Questions
Fundamental Rules Common Weakening 3 Incorrect Answer Simple Rule for
Scenario Traps weakening a
a. The stimulus will To weaken a ; Incomplete ; Opposite
contain an conditional info; answers;
argument; conclusion, attack
; Improper ; Shell game the necessary b. Focus on the comparison; answers; condition by conclusion; showing that the
; Qualified ; Out of scope necessary c. The info in the conclusion. answers. condition does not stimulus is suspect. need to occur in There are often order for the reasoning errors sufficient present, and you condition to occur. must read the
d. Weak questions
often yield strong
e. The answer
choices are accepted
as given, even if
they include “New”