theLSATguru
Subscribe
Logical Reasoning · argument structure

LSAT premise and conclusion analysis: strategy, examples, and practice drill.

The first skill that separates students who understand the passage from students who can actually answer Logical Reasoning questions under time.

A lot of students read an LSAT stimulus and think they understand it. Then they get to the answer choices and realize they never identified the author's actual point. That is where mistakes start. If you cannot separate the conclusion from the supporting premises, Flaw, Strengthen, Weaken, Necessary Assumption, Method of Reasoning, and Main Point questions become much harder than they need to be.

What is premise and conclusion analysis on the LSAT?

Premise and conclusion analysis means breaking an argument into two parts: the claim the author is trying to prove, and the evidence used to support that claim. The conclusion is the author's main point. The premises are the reasons, facts, examples, or evidence the author gives to support that point.

On the LSAT, the conclusion is not always the last sentence. Sometimes it appears at the beginning. Sometimes it is hidden after a counterpoint. Sometimes a stimulus contains no argument at all, just a set of facts.

Why this skill matters for Logical Reasoning

  • Main Point, you need to identify the author's central claim.
  • Flaw, you need to see how the support fails to prove the conclusion.
  • Strengthen, the correct answer improves the link between premise and conclusion.
  • Weaken, the correct answer attacks that link.
  • Necessary Assumption, the correct answer gives something the argument depends on.
  • Method of Reasoning, you need to describe how the author builds the argument.

If your argument map is wrong, your answer-choice analysis will usually be wrong too.

How to identify the conclusion

The conclusion is the claim the author wants you to accept. Look for indicators such as therefore, thus, so, hence, this shows that, for this reason, it follows that, and we should conclude that.

Do not rely only on indicator words. A better test is: which claim is being supported by the rest of the stimulus? If a sentence gives evidence, it is probably a premise. If a sentence receives evidence, it is probably the conclusion.

How to identify the premises

Premises are the reasons the author gives. Look for words such as because, since, for, given that, after all, research has shown, studies indicate, and the evidence is.

A premise does not need to be true in the real world. On the LSAT, you accept the premises as given and evaluate whether they support the conclusion.

The 3-step argument structure method

Step 1, Find the author's main claim. Ask: what does the author want me to believe? Do not confuse background information with the author's point.

Step 2, Find the support. Ask: why does the author think that claim is true? Everything that answers why is likely functioning as a premise.

Step 3, Test the link. Ask: do these premises actually prove the conclusion? Many LSAT arguments have clear premises and conclusions, but the support is still weak.

Common premise and conclusion traps

1. Mistaking a fact set for an argument

Some stimuli do not contain a conclusion. They simply describe a sequence of facts. If nothing is being argued for, do not invent an argument, the correct move is to notice the absence.

2. Treating a counterpoint as the conclusion

Words like although, admittedly, and some researchers claim often introduce views the author is about to push against. The sentence right after the counterpoint is usually the real conclusion.

3. Choosing the most interesting sentence

The conclusion is not the sentence that feels most important or most quotable. It is the sentence being supported by the rest of the stimulus. Function beats flavor.

4. Missing a minor conclusion

Some arguments contain both a minor conclusion and a main conclusion. A minor conclusion is supported by one premise and then used to support the larger point. Identify both, and know which one the question is asking about.

5. Evaluating the topic instead of the logic

You may have strong opinions about drone delivery, library policy, or wetlands. The LSAT asks whether the given premises support the given conclusion, not whether the conclusion is true in the real world.

Practice · 8 original drills

Try it yourself.

For each stimulus, identify (A) the conclusion, if any, (B) the premises that support it, and (C) whether the argument is strong or weak, and why. Click Reveal answer key to check your structure.

Drill 1 · Behavior-to-motive leap
Workplace Training
Reveal answer key ↓

At Norland Tech, employees who were offered a choice between attending advanced software workshops or short workshops in unrelated departments most often chose the unrelated workshops. Because of this, the training director concluded that employees are more interested in becoming broadly adaptable than in deepening their expertise in one technical area.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: Employees are more interested in becoming broadly adaptable than in deepening expertise in one technical area.

Premises: Employees most often chose the short workshops in unrelated departments over the advanced software workshops.

Strength: Weak. The argument jumps from a behavioral choice to a motive. Employees may have chosen the unrelated workshops because they were shorter, easier, better scheduled, less technical, or taught by more popular instructors.

Takeaway: Be careful when an argument moves from behavior to motivation. A choice does not automatically prove why the choice was made.

Drill 2 · Viewpoint contrast
Nutrition Tracking Apps
Reveal answer key ↓

Some wellness coaches argue that calorie-tracking apps improve eating habits mainly because they force users to think about food choices in the moment, not because they teach lasting nutrition principles. But that claim is questionable. A recent study found that users who tracked their meals consistently for several months were better able to estimate portion sizes even after they stopped using the app.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: The claim that tracking apps improve eating habits only through moment-to-moment awareness (rather than lasting nutrition learning) is questionable.

Premises: Coaches claim the benefit is temporary awareness; a study found long-term users estimated portion sizes better even after stopping the app.

Strength: Reasonably strong. The conclusion is modest, it merely calls the coaches' claim into question. The evidence suggests a lasting skill gain, which gives a reason to doubt the coaches' narrow claim.

Takeaway: A cautious conclusion is easier to support than an absolute one.

Drill 3 · Policy conclusion / no-better-alternative
Delivery Drones
Reveal answer key ↓

Delivery drones sometimes disturb nesting birds and can disrupt quiet residential areas. Even so, the city should not impose stricter rules on drone delivery companies, since no other delivery method currently reduces traffic congestion as effectively.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: The city should not impose stricter rules on drone delivery companies.

Premises: Drones can disturb birds and residential areas, but no other delivery method reduces traffic congestion as effectively.

Strength: Weak. The argument assumes the traffic benefit outweighs the harms. Stricter rules could target flight paths, hours, noise levels, nesting areas, or delivery volume without eliminating drones.

Takeaway: No better alternative does not automatically mean no regulation is needed.

Drill 4 · Counter-premise + conclusion indicator
Library Late Fees
Reveal answer key ↓

Admittedly, eliminating library late fees may reduce one source of library revenue. However, the purpose of a public library is to increase access to books, technology, and learning resources. Since late fees discourage some residents from returning to the library, the city should continue its policy of not charging late fees.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: The city should continue its policy of not charging library late fees.

Premises: The purpose of a public library is to increase access to books, technology, and learning resources; late fees discourage some residents from returning. The lost-revenue point is a counter-premise, not the author's view.

Strength: Moderately strong. The argument acknowledges a downside and gives a plausible mission-based reason for the policy. It does not claim the policy has no cost.

Takeaway: Words like "admittedly" often introduce a counter-premise rather than the author's main point.

Drill 5 · Recognizing a fact set
History of Navigation
Reveal answer key ↓

Before the development of reliable marine chronometers, sailors often struggled to determine longitude accurately at sea. The invention of more precise timekeeping devices allowed navigators to calculate longitude with far greater accuracy. Later improvements in mapmaking and astronomy further expanded the reliability of long-distance ocean travel.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: No conclusion.

Premises: None. The passage gives a historical sequence: longitude was hard to calculate, chronometers improved accuracy, later innovations improved ocean travel.

Strength: No argument to evaluate. This is a fact set, not an attempt to prove a claim.

Takeaway: Not every LSAT stimulus contains an argument. Do not invent a conclusion where none exists.

Drill 6 · Either / or, inclusive vs exclusive
Concert Schedule
Reveal answer key ↓

If Lena's message is correct, either the Friday concert or the Saturday concert will be postponed. But the venue manager said this morning that she is considering postponing both concerts and replacing them with one combined performance next month. Since the venue manager controls the final schedule, Lena is probably mistaken.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: Lena is probably mistaken.

Premises: If Lena is correct, either Friday or Saturday will be postponed. The manager is considering postponing both and controls the final schedule.

Strength: Weak. If both concerts are postponed, then at least one of the two is postponed. Unless "either" is used exclusively to mean one but not both, the manager's plan is actually compatible with Lena's claim.

Takeaway: Be careful with "either/or." A supposedly conflicting fact is sometimes compatible with the claim.

Drill 7 · Overbroad conclusion
Extreme Travel
Reveal answer key ↓

Any experience that helps someone develop courage is worth attempting. Therefore, even though some wilderness expeditions are dangerous, every person would benefit from attempting any wilderness expedition offered to them. After all, people often discover their own resilience only when they face situations that test their courage.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: Every person would benefit from attempting any wilderness expedition offered to them.

Premises: Any experience that helps develop courage is worth attempting; some expeditions are dangerous; people often discover resilience when they face courage-testing situations.

Strength: Weak. The premise only supports attempting experiences that help develop courage. The conclusion overextends to every expedition for every person, no matter how dangerous or ill-suited.

Takeaway: Watch for overbroad conclusions. Some valuable experiences are difficult does not prove all difficult experiences are worth attempting.

Drill 8 · Swapped standard
Wetland Development
Reveal answer key ↓

A proposed housing development would remove part of a wetland used by several frog species during breeding season. The developer argues that the project should face no serious environmental objection because none of the frog species is known to be dangerous to humans, and many animals that are harmless to humans are not legally protected.

  1. What is the conclusion of the argument, if any?
  2. What premises support that conclusion?
  3. Is the argument strong or weak? If weak, explain why.

Conclusion: The housing project should face no serious environmental objection.

Premises: The project would remove part of a breeding wetland; the frogs are not dangerous to humans; many harmless animals are not legally protected.

Strength: Weak. The argument changes the standard. Environmental concern depends on ecological importance, vulnerability, habitat loss, and legal protection, not whether a species is dangerous to humans.

Takeaway: Do not let an argument swap in an irrelevant standard.

Reading LSAT arguments the wrong way costs points.

Premise and conclusion analysis touches Flaw, Strengthen, Weaken, Assumption, Main Point, and Method questions. The free diagnostic shows you which of those is actually costing you, in five minutes.

Take the free diagnostic →Work with a tutor

Frequently asked questions

What is a premise on the LSAT?

A premise is a reason, fact, or piece of evidence used to support a conclusion. Premises often appear after words like because, since, given that, or research has shown.

What is a conclusion on the LSAT?

A conclusion is the claim the author is trying to prove. It may appear at the beginning, middle, or end of the stimulus, the last sentence is not automatically the conclusion.

Can an LSAT stimulus have no conclusion?

Yes. Some stimuli are fact sets, not arguments. If no claim is being supported by another claim, there is no conclusion to identify, do not invent one.

Why do I keep missing argument-structure questions?

Usually because you are reading for topic instead of function. You may understand what the passage is about without knowing which sentence is the conclusion and which sentences support it.

What question types require premise and conclusion analysis?

Main Point, Method of Reasoning, Flaw, Strengthen, Weaken, Necessary Assumption, Sufficient Assumption, and Principle questions all depend on argument-structure accuracy.

What to study next

Main Point Questions

Identify the author's central claim on demand.

Flaw Questions

Diagnose exactly how the support fails to prove the point.

Strengthen Questions

Improve the link between premise and conclusion.

Back to all question types · What is the LSAT?

Original LSAT-style drills for instructional purposes. Not official LSAT questions. LSAT is a registered trademark of the Law School Admission Council, which does not endorse this site.