Three Families of Logical Reasoning - Answers 1. Implication
2. Characterization
3. Operation
Implication Family - Answers -Require you to look for the ___ of an argument or data using given
facts
-Assume stimulus is true; facts must be stated outright or must be true based on what's known from
the stimulus
-Question types are MBT, sMBT or MBF
Operation Family - Answers -Requires manipulation of the argument
-Assume answer choices to be true, therefore correct answer will affect stimulus
-Question types are strengthen/weaken, crux, necessary/sufficient assumption, resolve/explain
Characterization Family - Answers -Requires analysis of the argument
-Describe or ___ what the stimulus is doing: stimulus offers argument, prompt asks you to pick an
answer that accurately describes something about it or mirrors it
-Question types are main point, describe how author of stimulus reaches conclusion, describe what is
wrong with position in stimulus, describe point of disagreement btwn. multiple speakers
Conclusion - Answers Point of an argument; what it is trying to prove
Premises - Answers Reasons/support for conclusion
Assumptions - Answers Unstated premises that the author implicitly believes
Shift words - Answers Words in an argument that introduce new points of view or a "shift" in fact
But, however, besides, etc.
Words indicative of premises - Answers Since, because, for, as, after all, moreover, in addition, given
that, while
Words indicative of conclusions - Answers Therefore, thus, hence, so, as a result, consequently, it
follows that, it is clear that
Value judgments - Answers Reveal author's attitude; "should"
Example: The showrunners of Game of Thrones screwed up colossally with its final season. To see
this, just consider that the most talked-about show for a decade has completely fallen out of the
Zeitgeist after it ended.
Validity - Answers A property of an argument that logically follows the premise, and conclusion is not
stronger than premises- NOTE: not synonymous with credibility!
"truth of the premises guarantees truth of the conclusion"
Temporal Fallacy - Answers attempt to draw conclusions about one time period from premises about
another time period
Correlative/Causative Fallacy - Answers assuming that correlation proves causation
Conditional Statements - Answers Assert the existence of a hypothetical relationship between
conditions; such as if the first condition was met, then the second must follow
Valid inferences - Answers Affirmation
Contrapositive
Contrapositive - Answers Switch and negate the terms; A --> B :: nB --> nA
Invalid inferences - Answers Fallacy of the converse
Fallacy of the inverse
Fallacy of the Converse - Answers Switches both conditions without negating them
A --> B :: B --> A
Fallacy of the Inverse - Answers Negating both conditions without switching them
A --> B :: nA --> nB
Sufficient Condition Keywords - Answers If, when, whenever, all, any, every, each, the only,
guarantee
Necessary Condition Keywords - Answers Then, only if, only, only when, needs, require, must, always
Properties of "If and/but only if" - Answers Biconditional relationship; both sufficient and necessary
conditions
, Properties of "unless", "without", "until", "except" - Answers Negate sufficient conditions, transform
into "if __ not"
Indicator of the contrapositive, watch for inverse fallacies!
Properties of "No", "none" - Answers Negate necessary conditions; translate to "does not"
Transitive Property - Answers If the necessary condition of one statement matches the sufficient
condition of the other, then you can connect the two statements
A --> B and B --> C :: A --> C
Transitive Fallacy - Answers A --> B and A --> C :: B --> C
Sufficient Conditions - Answers Conditions that are enough to guarantee that a necessary will follow
if satisfied; nothing else is required
Necessary Conditions - Answers Introduce new points of view
Required in order for a sufficient condition to be satisfied; without it, the sufficient cannot occur
Logical Force - Answers -The measure of how strong a proposition is
-Usually communicated by words that are small and easily overlooked
-Most important in Characterization questions (esp. parallel)
-Weak conclusions are easier to support
Modality - Answers The degree of necessity expressed by a proposition; how certain it is that
something will occur
Weak Modality Words - Answers Possibility; more than 0% chance of occurence
May, could, might, can, occasionally, significant, often
Moderate Modality Words - Answers Probability; more than 50% chance
Probably, likely, usually
Strong Modality Words - Answers Necessity; 100% chance
**Actionable**, best statements to use when making deductions
Will, must, definitely, always, is/are, necessarily, do/does
Quantification - Answers The proportion of a group that has been given property; how many things
have a certain quality?
Weak Quantification Words - Answers Possibility; at least 1
Some, a few, several, many, a significant number
Moderate Quantification Words - Answers Probability; more than half
Most, majority, over half
Strong Quantification Words - Answers Necessity; 100%
**Actionable**, best statements to use when making deductions
All, any, each, every
Most v. The Most - Answers Comparisons between absolute and comparative claims- "Most" is
absolute and "The Most" is comparative
Must Be True (MBT) - Answers -Most common question type in implication family
-Answer MUST be inferrable!
-Identify what follows from the facts the question presents
-Accept stimulus as true no matter what- Correct answer will be inarguably valid based on stimulus
-Use conditional reasoning to draw logical conclusion from given statements
-NOTE: pay attention to logical force of stimulus and answer choices: strong statements, weak answer
choices
Must Be True (MBT) Prompts - Answers "must be true", "follows logically", "logically completes",
"properly inferred"
Incorrect Answers for MBTs - Answers -Anything outside the scope of the stimulus or contradicts it
-Generalizes from one specific situation
-Commonly give hypothetical situations that differ from the stimulus
-Try to explain what caused something to happen
-Language of answer choice is stronger than stimulus