LSAT Logical Reasoning Vocabulary

A comprehensive set of vocabulary flashcards covering answer-choice traps, assumption types, logical flaws, and question strategies presented in the LSAT logical-reasoning lecture.

Outside the Scope

A wrong answer that introduces information irrelevant to the stimulus and question stem.

Irrelevant Comparison

A choice that compares two things in a way that has no bearing on the question being asked.

Extreme Answer Choice

An option containing language (e.g., always, never) too strong to be supported by the stimulus.

Distortion

A wrong answer that cites details from the passage but twists their meaning.

180 Answer

A choice that says the opposite of what the correct answer must say.

Faulty Use of Detail

An answer that accurately states a stimulus detail but fails to address the question.

Intermediate Conclusion

A statement supported by evidence that itself supports the main conclusion.

Point at Issue

A statement about which two speakers both express an opinion and disagree.

Analogy (Method)

Arguing by pointing out relevant similarities between two situations.

Example / Counterexample

Providing an instance that illustrates or contradicts a general claim.

Appeal to Authority

Supporting a claim by citing someone deemed an expert.

Elimination of Alternatives

Arguing that one option must be true by ruling out all others.

Ad Hominem

Attacking an opponent’s character instead of the argument.

Means / Requirements Reasoning

Claiming that a certain means is necessary to achieve an end.

Formal Logic Trigger

Strong wording (if, only if) that signals sufficient–necessary relationships.

Contrapositive

A logically equivalent statement formed by flipping and negating terms of a conditional rule.

Parallel Reasoning

A question asking for an argument with the same logical structure and conclusion strength.

Assumption

An unstated premise needed for the conclusion to follow from the evidence.

Sufficient Assumption

A missing premise that, if added, guarantees the conclusion is true.

Necessary Assumption

A premise that must be true for the conclusion to hold, though it alone may not prove it.

Principle Assumption

A broad rule bridging evidence and conclusion, often phrased generally in the correct answer.

Mismatched Concepts (MMC)

When evidence and conclusion involve different ideas that need a connecting assumption.

Overlooked Possibilities (OP)

Potential alternative explanations or factors the author fails to consider.

Proof Test

Checking if adding an answer choice to the argument makes the conclusion logically follow.

Flaw Question

Tasked with identifying the error in the author’s reasoning.

Alternative Possibility Flaw

Erroneously concluding one explanation is the only one when others exist.

Unwarranted Assumption Flaw

Relying on an unstated belief; answer phrases include “takes for granted” or “presumes.”

Necessity vs. Sufficiency Flaw

Confusing a sufficient condition with a necessary one or vice versa.

Representativeness Flaw

Drawing a conclusion about a broader group from an unrepresentative sample.

Part vs. Whole Flaw

Attributing a property of a part to the whole or the whole to a part.

Scope Shift

Switching topics or concepts between evidence and conclusion without justification.

Correlation vs. Causation Flaw

Assuming that because two events correlate, one causes the other.

Opinion vs. Fact Flaw

Treating a belief or opinion as if it were proven fact.

Number vs. Percent Flaw

Mistaking percentage information for absolute numbers, or vice versa.

Possibility vs. Certainty Flaw

Basing a definite conclusion on evidence that only shows possibility.

Equivocation

Using a word in two different senses as if the meaning remained constant.

Circular Reasoning

Using the conclusion as its own justification; evidence merely restates the claim.

Evidence Contradicts Conclusion

Citing facts that actually undermine rather than support the stated conclusion.

Absence of Evidence Flaw

Treating lack of proof as proof of the opposite position.

Parallel Flaw Question

Requires matching an argument that contains the same reasoning error as the stimulus.

Parallel Principle Question

Finds an argument that applies the same general rule identified in the stimulus.

Inference Question

Asks what statement must be true based solely on the provided information.

Paradox Question

Seeks an answer that best resolves an apparent contradiction in the facts.

Main Point Question

Requires identifying the primary conclusion of the argument.

Role of a Statement

Determines how a particular sentence functions within the argument structure.

Method of Argument

Describes the technique or approach the author uses to make the case.

Strengthen Question

Ask for new information that makes the conclusion more likely to be true.

Weaken Question

Ask for information that makes the conclusion less likely to be true.

Evaluate the Argument Question

Seeks a consideration whose answer would most affect the argument’s strength.

Decision Tree (Point at Issue)

A mental checklist: Does each speaker have an opinion on the statement, and do they disagree?

Strategy Sheet

A compiled list of common flaws and tasks used to approach LSAT logical reasoning questions.