LSAT Logical Reasoning Question Types

Flawed Reasoning

  • Question types:
    • "The argument is most vulnerable to criticism on which one of the following grounds?"
    • "The reasoning in the argument is flawed in that it:"
  • Answer types:
    • Abstract description of bad reasoning
    • What the argument overlooks (analyzed by Weaken answers)
    • What the argument assumes (analyzed by necessary assumption answers)
  • Identify why the conclusion doesn’t have to be true even if the premises are true (common flaws).
    • Examples of common flaws:
      • Circular reasoning
      • Cause and effect
      • Mixing up sufficient and necessary conditions
      • Mixing up words
      • Ad hominem
      • Part to whole
      • Whole to part
  • Be careful of answers that misdescribe the conclusion.
  • Correct answers must:
    • Be descriptively accurate
    • Constitute bad reasoning

Strengthen

  • Question types:
    • "Which of the following, if true, most strengthens the author’s reasoning?"
    • "Which of the following, if true, most supports the author’s reasoning?"
    • A Strengthen question stem may say "most strongly supported". You can tell it is a strengthen question because the question will say "the CONCLUSION is most strongly supported if"
  • Extremely similar to weaken questions.
  • Core technique: Identify the conclusion and reasoning, work out what the author is trying to say, and figure out what’s wrong with it. The job is to pick an answer that helps fix this problem.
  • Common Trap answer type: Answers which can be interpreted weakly, answers with the word “some”.
  • The stronger and less flexible the answer, the better, as long as it is on point.
  • Think about why the conclusion doesn’t necessarily have to be true even if the premises are. This identifies the gap.
  • Pay attention to info that shows up in the conclusion but not in the premises.
  • Be ready for arguments where the author gives a hypothesis for a phenomenon and think of alternate hypotheses.
  • The correct answer doesn’t need to guarantee the conclusion, just make it more likely.
  • If the argument includes correlation or explanations for a phenomenon, be ready for answers that eliminate an alternate hypothesis (not always the right answer, but common).
  • Question types from most common to least: the most common type of LR question
  • Method:
    • Identify premise and conclusion

Weaken

  • Question types:
    • "Which of the following, if true, most weakens the author’s reasoning?"
    • "Which of the following, if true, most undermines the author’s reasoning?"
  • Think about why the conclusion doesn’t necessarily have to be true even if the premises are. This identifies the gap.
  • Pay attention to info that shows up in the conclusion but not in the premises.
  • Be ready for arguments where the author gives a hypothesis for a phenomenon and think of alternate hypotheses.
  • Strong answers are great on weaken questions. Never eliminate an answer because it is “too strong”.
  • Common Trap answer type: Answers which sound good but can be interpreted weakly. Answers with the word "some".
  • Correct answer doesn’t need to falsify the conclusion, just make it weaker. If there are multiple answers that do that choose the one that weakens the most
  • If the argument includes correlation or explanations for a phenomenon, be ready for answers that eliminate an alternate hypothesis. Isn’t always the right answer but is common

Necessary Assumption

  • Question types:
    • "Which one of the following is an assumption required by the argument?"
    • "The argument relies on assuming which one of the following?"
  • Necessary assumption questions have a gap between conclusion and reasoning.
  • The author may shift terms in a way that may feel reasonable, but isn’t. The assumption is that the two terms are related – an assumption is anything we think is true but isn’t directly stated.
  • Spot the switch between terms (generally between conclusion and reasoning) and look for a word or concept shift.
  • The right answer will link together both of the concepts in question.
  • Negation technique: Does the negation of this answer make it impossible for the conclusion to logically follow from the premise? If yes then that’s the right answer.
  • Catching where the argument has swapped terms and looking for the answer which links both terms is more important than the negation technique.
  • Strong answers are generally bad on necessary assumption questions.
  • Method:
    • Don’t rush to the answers without finding the flaw
  • Example: "You exercise regularly, so you’re sure to be in good health." The argument doesn’t tell us anything about how exercise relates to good health. The right answer might be something like "Exercise is beneficial for health". If this isn’t true, if exercise isn’t beneficial for health, then we have no argument.

Must be True

  • Question types:
    • "If all the statements above are true, which can be properly inferred?"
  • Non-argument questions (generally won’t have a conclusion and instead will just be a series of statements).
  • The answer will be something that is 100% true if the stimulus is true.
  • Do not need any extraneous assumptions so any choice that includes info not provided in stimulus is likely to be untrue
  • Be careful about choosing strong answers like All, Every. Weak answers Some, Possibly, are more likely to be correct
  • Conditional diagramming is useful

Sufficient Assumption

*Question types:
* "The conclusion drawn above follows logically if which one of the following is assumed?"
* "The conclusion of the argument can be properly drawn if which one of the following is assumed?"

  • You have to prove the conclusion 100% true.
  • These are technically flawed argument questions, but they are different in that your goal is to help prove the argument correct
  • Diagramming is useful
  • Best solution: Focusing on the conclusion first and filling in evidence
  • Common Trap answer type: A reversal or incorrect negation of the right answer
  • Most involve bridging gaps in conditional logic.
  • If stuck on an answer ask if that combined with the premise guarantees the conclusion
  • Think about contrapositives, they’re popular.
  • Be careful with weakly worded answers because they barely ever guarantee the conclusion

Most Strongly Support

  • Question types:
    • "Which of the following is most strongly supported by the information above?"
  • Very strongly supported, might not be 100% true
  • Simplify the facts so you can more easily spot how they connect
  • You generally shouldn’t diagram MSS questions. Because they are only ~80% supported, they don’t tend to chain conditional statements together
  • Be careful bout choosing strong answers like All, Every. Weak answers Some, Possibly, are more likely to be correct
  • Do not need any extraneous assumptions so any choice that includes info not provided in stimulus is likely to be untrue
  • Method:
    • No need to identify conclusions and premise
    • Think about why the conclusion doesn’t necessarily have to be true even if the premises are. This is the gap
    • Pay attention to info that shows up in conclusion but not in premises
    • No need to identify premises and conclusions

Main Conclusion / Identify The Conclusion

  • Question types:
    • "Which one of the following most accurately expresses the conclusion drawn in the argument?"
    • "The conclusion drawn in the argument is that"
  • Identify the main conclusion.
  • Often it’ll be framed as a rejection of another belief like “This belief is false.”
  • If stuck between two answers ask which one supports the other, and the one being supported is likely to be the right answer
  • The right answer is a restatement of the conclusion and the wrong one will typically take the conclusion too far
  • To get better at this question type, look for indicator words and ask yourself "why is the author telling me this?"

Role in Argument

  • Question types:
    • "Which one of the following most accurately describes the role played in the argument by the claim that… "
    • "The claim that [X]m plays which one of the following roles in the argument?"
  • Role in Argument questions will sometimes use intermediate conclusions.
  • An intermediate conclusion is something supported by a premise and which in turns supports another conclusion. Example: You are studying for the LSAT, so you must be applying to law school, so you must want to be a lawyer. The middle part is an intermediate conclusion supported by the first part.
  • An intermediate conclusion is both a conclusion and a premise.
  • Think about the role of a specific statement AFTER you do the identifying part.
    • Is it part of the author’s argument?
      • If yes, then is it a premise, intermediate conclusion, or conclusion?
    • If not part of the argument, what is it?
  • You can also take two statements and try reversing their order to see which way makes sense. Example: “Dogs are great, because they are cute” vs. “Dogs are cute, because they are great”. The first one makes more sense.
  • Wrong answers can either misinterpret and misconstrue the conclusion or describe other parts of the stimulus that aren’t being asked about.

Method of Reasoning

  • Question types:
    • "Which one of the following is a method of reasoning used in the argument?"
  • Try to find reasoning method: rule-application, analogy, phenomenon-hypothesis, generalization, cost/benefit, etc.
  • Very abstract answers, if you can’t match part of the answer to the stimulus it’s wrong
  • Method:
    • Read stimulus, identify conclusion and premises
    • identify premise and conclusion

Evaluate

  • Question types:
    • "Which one of the following would be most useful to know in order to evaluate the argument?"
  • A lot in common with Strengthen and Weaken questions. Use the same process as on these: find the conclusion, find the reasoning, identify the flaw. Then, pick an answer which addresses this flaw no matter how you interpret it.
  • Answers with “some” or answers that can be interpreted very weakly are generally not going to be correct.
  • Answers are usually phrased in the form of a question.
  • What would happen to the argument if you responded reductio ad absurdum both ways

Resolve, Reconcile and Explain / Paradox

  • Question types:
    • "Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above?"
    • "Which one of the following, if true, does most to justify the doctors’ apparently paradoxical belief?"
  • Common Trap answer type: Something which may be true but doesn’t explain the situation. Something that merely explains one part.
  • Figure out what is confusing about the situation.
  • It’s okay for the right answer to require a small reasonable assumption

Parallel

  • Question types:
    • "The pattern of reasoning in the argument above is most similar to that in which one of the following arguments?"
    • "Which one of the following arguments is most closely parallel in its reasoning to the argument above?"
  • Method:
    • Look for patterns in arguments
    • Condense those patterns
    • Quickly evaluate the answers to see which ones do NOT share the pattern
    • Evaluate the remaining 1-2 answers more intensely to make sure they match
  • About half of parallel questions will use conditional language. You should generally diagram these, then scan for matching elements. The other parallel questions require you to sum up the pattern in a few words and try to match it.
  • Common Trap answer type: One with similar language, or a similar structure except for one element.
  • If stuck on an answer, check if strength of answer matches strength of conclusion. Ex: if answer says X might occur but conclusion says X will occur then probs not right

Parallel Flaw

  • Question types:
    • "Which one of the following arguments contains flawed reasoning that is most parallel to that in the argument above?"
    • "The flawed pattern of reasoning in the argument above is most similar to that in which one of the following?"
  • Nearly identical to parallel
  • Best Solution: Sum up arguments by diagram or in plain English. Scan answers to spot most likely matches
    • Look for patterns in arguments
    • Condense those patterns
    • Quickly evaluate the answers to see which ones do NOT share the pattern
    • Evaluate the remaining 1-2 answers more intensely to make sure they match
  • If stuck on an answer, check if strength of answer matches strength of conclusion. Ex: if answer says X might occur but conclusion says X will occur then probs not right
  • Common Trap answer type: One with similar language, or a similar structure except for one element.
  • Some involve diagramming, others involve summarizing a pattern and spotting it. The difference in diagramming is that you need to be familiar with flawed methods of diagramming: incorrect negation, incorrect reversal, trying to attach a quantity word to a necessary condition, etc.
  • Remember correct answer has same flaw

Point at Issue

  • Question types:
    • "James and Yardley disagree with each other about which one of the following?"
  • Point at Issue questions involve a disagreement between two people.
  • The right answer will be one where:
    • Both people have an opinion
    • One person says yes, the other says no
  • If you haven’t got a “yes” and a “no”, then you haven’t got the right answer. The yes or the no can come from what is directly stated or what can’t be denied based on what was stated. For example, if you say “I want a good LSAT score to help with my applications” then you basically can’t deny that you are applying to law school. You didn’t directly say you were, but the LSAT isn’t useful for any other kind of application.
  • Method:
    • Break down Person 1’s statement
    • Break down person 2’s statement
    • Think about whether they disagree ab a premise, conclusion or something else
  • Common Trap answer type: Answers which only one person has an opinion about