LSAT Principle Questions, Part II (Question Types)

Update 2015: Practice makes perfect. You can find a list of principle questions + explanations for those questions here:


In part one of this post on LSAT Principle questions, I covered what a “principle” is.

Now, in part II, I’m going to tell you about the main types of principle questions that appear on the LSAT.

Check out Part III for explanations to a few sample principle questions, and a list of all the principle questions from LSATs 29-38.

First, A Warning

I don’t think questions types are very important. You don’t need to memorize these types, and learning them won’t help you very much if you’re having trouble with the underlying concepts (conditional statements, applying a rule to a situation, assessing an argument, finding conclusions, etc.)

So don’t get hung up on the technical details. That said, I think going over the questions types can be somewhat useful for two reasons:

  1. The question types test different skills. If one type of question seems much harder to you than the others, then you know you need to focus on the skills needed to answer that type of question.
  2. Different question types have different requirements for choosing the right answer. It’s surprisingly common for students to answer questions wrong because they misunderstood what they were being asked. Studying the question types can help you get used to what you’re being asked to do.

Beyond that, I’ve rarely seen students get any results from studying questions types. So please don’t try to memorize this information.

Types Of LSAT Principle Questions

The three main types of LSAT Principle questions are:

  1. Strengthen
  2. Parallel Reasoning
  3. Extraction

Strengthen Principle Questions

Strengthen questions are the most common type of principle questions. They are the simplest principle questions; they’re just like the regular strengthen questions.

  • The stimulus will be an argument.
  • There will be a flaw in the argument.
  • You can make the argument stronger by addressing the flaw.

The only difference is that the right answers will be principles. You must pick one that, if true, would force someone to believe the argument was stronger.

As with all questions based on arguments, it’s very important to identify exactly what the conclusion of the argument is. It’s surprisingly hard to identify conclusions correctly, and most people are bad at it.

If you find yourself unsure, pick some questions, try to find the conclusions, and then explain to a friend what the conclusion of each argument is, and why. Or post the same on a LSAT forum. This sounds silly, but it’s one of the best ways to get better at finding conclusions. If you’re not getting them 100% of the time, then don’t kid yourself: you don’t fully understand arguments, and you need practice.

Question Stems for Strengthen Principle Questions

  • Which of the following principles most helps to justify the argument?
  • Which principle would provide the most support for the argument?
  • Which principle would most strongly support the argument?

All of these questions stems ask you to help the argument. You don’t need to prove the conclusion correct. You just have to make the argument somewhat stronger.

Parallel Reasoning LSAT Principle Questions

These questions are closest to parallel reasoning questions. In parallel reasoning questions, you must figure out the structure of the argument in the stimulus. Then you find the argument in the answer choices that has the same structure.

You answer parallel reasoning questions using the same process. Find the principle illustrated by the stimulus. Then find the answer choice that illustrates that same principle.

Sometimes, Principle Parallel Reasoning questions give us a situation that illustrates a principle (without stating it explicitly). We have to find out what the principle is, and then find a situation that matches.

Other times, the stimulus will explicitly state a principle, and we must find a situation where that same principle applies.

In either case, it’s the same process: identify principle, apply to new situation.

Powerscore calls these questions “Must be True” principle questions, but I have no idea why. They have nothing in common. In those questions, we make a conclusion from a set of facts (not an argument). In parallel reasoning principle questions, we have to find a situation that matches the stimulus.

Question Stems For Principle Parallel Reasoning

These question stems don’t say the words “Parallel Reasoning”. That’s what makes principle questions so hard to classify. But if you look at some examples, you’ll see that questions with these question stems all ask you to do the same thing: find a parallel situaiton.

  • Which of the following situations most conforms to the principle illustrated above?
  • Which of the following illustrates a principle most similar to that illustrated above?
  • Which one of the following judgements conforms to the principle stated above?

Principle – Extraction Questions

These questions present a situation that illustrates a principle. The answer choices list five principles. You have to figure out which one matches the principle illustrated by the stimulus.

I call these “extraction” questions because you have to extract the principle that’s within the argument.

Essentially, these questions ask you to identify an assumption made in the argument.

They are somewhat similar to necessary assumption questions, with one major difference: the assumptions in principle questions tend to be warranted assumptions, and the arguments tend to be good arguments.

Not all assumptions are errors. We make many warranted assumptions in everyday conversation. If I say “I will meet you at the cafe tomorrow”, I am assuming:

  • The cafe will not burn down.
  • I will survive until tomorrow.
  • You won’t get kidnapped before meeting me.

These are all reasonable assumptions, and therefore, they are warranted assumptions. In general, if everyone would tend to agree that an assumption is reasonable, then it is warranted.

Necessary assumption questions make unwarranted assumptions. Necessary assumption questions present flawed arguments.

These principle questions instead make reasonable assumptions. We have to extract the principle that underlies the stimulus.

These are the closest thing to a “pure” principle question type. The stimulus presents a situation, and then five principles. You have to choose the principle that best fits the situation. This has no parallel with other question types.

Note: Powerscore calls these “Justify” or “must be true” questions. Again, I’m not really sure why. But principle questions are hard to classify, and it’s best not to get hung up on which words to use.

Principle – Extraction Question stems

  • Which of the following principles underlies the argument?
  • The reasoning most closely conforms to which principle?
  • The facts conform to which generalization?

The answer choices will always be principles, and the stimulus will be an argument or set of facts that illustrates a principle.

Watch Out For “Conforms”

Vocabulary: Watch out for the word “conform”! It isn’t always used in the same way. Here are two question stems which use it differently:

  • “Which of the following situations conforms most closely to the principle illustrated in the stimulus”
  • “Which of the following principles conforms most closely to the situation in the stimulus”.

Did you notice the difference? The first type gives us a principle in the stimulus (e.g. children should not play unless they clean their room and eat their dinner). The answer choices will be five situations involving children playing, and we have to decide which one is justified by the stimulus. That’s a parallel reasoning principle question.

The second question stem presents us with a situation, and asks which principle conforms with that situation. This is asking us to extract the principle that can be found within the stimulus.

New Types of Principle Questions

The more recent LSATs have introduced a few different types of principle questions. They’re pretty rare, so there’s no point trying to memorize the new types. But if you want to have a look, I’ve listed a few below:

LSAT 64, section I, question 21: Flawed reasoning principle question

LSAT 63, Section I, question 18: Application Principle Question – Strengthen

LSAT 63, Section III, question 22: Application Principle Question – Sufficient Assumpton

Did that answer all of your questions about principle questions? Is there anything you still want to learn about? Let me know in the comments!

Check out Part III for explanations of sample principle questions, and a list of principle questions from LSATs 29-38.

2 thoughts on “LSAT Principle Questions, Part II (Question Types)

  1. Hello and thank you for your intentions to help with these posts!

    I was wondering, when dealing with principle questions (whether strengthen, parallel reasoning or extraction) is there a trick of finding out the correct answer of a principle question via fitting the necessary part of the principle with the answer choice or vice-avers?

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