LSAT Logical Reasoning

 LSAT Logical Reasoning

There are 17 to 19 question types in the Logical Reasoning section and having a clear strategy for each question type will improve your accuracy and speed.

lsat logical reasoning

I divide question types in two main categories:

Those in which you have must identify the conclusion are:

  1. Flaw
  2. Strengthen
  3. Weaken
  4. Necessary assumption
  5. Sufficient assumption
  6. Main Point
  7. Method of reasoning
  8. Parallel Reasoning
  9. Parallel flaw
  10. Role
  11. Resolve
  12. Explain
  13. Agree or Disagree
  14. Evaluate
  15. Principle

Those in which you don’t have to identify the conclusion are:

  1. Must be true or Must Be false
  2. Most strongly supported

LSAT Logical Reasoning Question Parts

There are three  parts of a logical reasoning question.

First part is the Stimulus, the short paragraph on the top.

Then there’s the Question or the prompt in the middle

And then, there are five Answer choices

Let’s talk about the stimulus.

A stimulus can have four parts:

  1. Premises
  2. Conclusion
  3. Secondary conclusion
  4. Assumptions

Premises are information in the stimulus that support the conclusion. The whole purpose of their existence is to make a way for conclusion. An argument cannot just make a statement. It has to provide some evidence to support that statement, and that evidence is the premises.

For example, there might be a stimulus that argues that Muhammed Ali is the best boxer of all time. That stimulus will provide some evidence to support the claim why he is the best boxer. What was special about Muahmemd Ali that makes him the best boxer. The Part that says he is the best boxer is the conclusion, and all the information to support the conclusion is the premises.

An argument-based stimulus will always have a conclusion with rare exceptions. 16 out of 19 question types are the argument-based questions. And it is imperative to identify the conclusion in them. Conclusion is the part that most of the stimulus is designed to support. But I must say again, not all stimulus have a conclusion. Some will have just facts or information.

Sometimes, you will have to deal with Secondary-conclusion. Secondary conclusion has its own evidence in the stimulus but it’s not the main conclusion. It is introduced to support the main conclusion.

Lastly, you also have to be prepared for assumptions.  Assumptions are like gowssstt-premises. You can’t see them but they are there. Basically, it’s the information that the author assumes is true to support the author’s conclusion. You will never see them written in the stimulus. They are just “assumed” and they exist between the premises and the conclusion.

Let’s move to our GENERAL STRATEGY in the section

First step is to the Read the question. Always read the question before the stimulus so you know what you have to look for. In each question type, we are looking for unique information. If you read the stimulus first and then read the question, there are good chances that you will go back to stimulus and look for the information that you need to answer that question. But if you read the question first you are saving time by not having to read the stimulus twice.

Second step is to Identify the question type and recall the task. It’s very important to tell yourself what you are going to look for in the stimulus. Few seconds spent recalling the strategy will help you find the right answer fast. And so, before you do the stimulus, tell yourself clearly what you are going to do. For example, if it is a weaken question, I will tell myself that I have to find the conclusion and weaken it. It really is that simple but extremely important.

Third step is to read the stimulus and identify the conclusion. This step will not apply on information-based questions such as Must be true and most strongly supported. But in argument-based questions, It is crucial to identify the conclusion. After identifying the conclusion, move to the fourth step.

Fourth step is to predict the answer. This will be possible only in argument-based questions, question types that have conclusion. Your prediction doesn’t have to be too specific. I will show you later how making even a general prediction can improve your speed and accuracy.

Fifth and last step is to go to answer choices and carefully eliminate wrong ones. Read the answer choices in the order given. If you find an answer choice that matches your prediction, choose it and move to the next question. But if you are not certain about any of the options then eliminate all answer choices that are clearly wrong and narrow down your options to 2. It is much easier to identify the right answer choice when there are fewer options to choose from.

Remember, there is only one correct answer choice and four incorrect answer choices. There is no such thing as one answer choice is better than the other. Either its right or wrong, quite objectively. The four wrong answer choices are completely incorrect. An answer choice which is partially incorrect, is also completely incorrect.

Just try to follow the steps,  especially the step of making a prediction, and go through answer choices confidently.

Let’s learn how to identify a conclusion

 There are 3 ways to identify a conclusion in a stimulus LSAT Logical Reasoning Conclusion is the crown of the argument. It’s imperative to identify it before one goes to the answer choices in argument-based questions. Also, conclusion could be anywhere in the stimulus. It could be in the first sentence, middle sentence or the last sentence. With that being said, let’s move on to the 3 ways to identify the conclusion. First and easiest way to find the conclusion is by looking for keywords: Words such as Therefore, consequently, thus, hence, so, accordingly, it follows that, hint towards conclusion. Identifying premises can also help distinguish conclusions from the premises. To identify premises, look for keywords such as Since, because, for, after all,, in addition, given that. Sometimes, contrast words also lead to the conclusion. Pay attention to words such as: but, yet, in contrast, instead, although, alternatively, rather, nevertheless, nonetheless and the list goes on. However, do not rely uncritically on these indicator words. They can be misleading. There is no completely mechanical way of identifying the conclusion within an argument. Second way to find the conclusion is to look for statements or words that sound like opinions: words such as should and must and statements which are the author’s opinion are typically the main conclusion of the argument. Third way to find the conclusion is to look for a sentence that is supported by most of the other sentences, but it doesn’t support anything. Main conclusion of an argument is the logical end of the argument. It could be in the first sentence but it does not support anything else in the argument. However, most of the sentences in the argument support it.Logical Reasoning Practice QS

Conditional Statements

One of the highly tested concepts in the LR and LG section is the conditional statements. It is critical to understand this concept. In many questions, your accuracy will depend on recognizing and drawing the conditional statements. It’s not a hard concept, it’s just something that you probably haven’t done before.

Let’s see how they are different from simple statements LSAT Logical Reasoning.

Here’s an example of a simple statement: Access Prep loves helping people get into law school.

It’s simple, straightford and not dependent on any other statement. Conditional statements are not. In conditional statements, one statement is dependent on another. If a necessary condition does not happen, sufficient cannot happen.

Here’s an example of a conditional statement:

If you love helping people get into law school then you teach LSAT.

Which means that If you love to get people in law school, then you must teach LSAT and if you don’t then you actually don’t love helping people get into law school then you teach LSAT.

Let’s not worry about whether it is fair to say that or not. Let’s just identify two parts of conditional statements and draw them.

Most of the time, they will be in an “If- then” relationship. “If” one happens, “then” the other one must happen.

The statement that comes right after “if” is a sufficient condition and the other part is a necessary condition.

In above case, “love helping people get into law school then you teach LSAT” is sufficient condition and

“you teach LSAT” is a necessary condition.

We represent conditional statements with an arrow between them. Sufficient conditions come on the left side of the arrow and necessary on the right side of the arrow.

Sufficient condition , arrow, and then necessary condition.

love getting people in law school 🡪 Teach LSAT

We can abbreviate them to save time on the test day. It will look like this:

LGPL → TL

Sufficient condition is enough to guarantee the necessary condition. When sufficient happens, necessary must happen. It’s not possible to have sufficient condition without the necessary condition.

It’s just how water is necessary for fish to survive. Our fish is sufficient condition and our necessary condition is the water.

Can we have live fish without water? We cannot.

But, can we have water without fish in it? Yes we can!

This brings me to my second important point: we can have necessary condition without sufficient condition. Necessary condition can exist without sufficient condition. Everything that comes on the right side of the arrow can exist without the thing on the left side of the arrow.

However, if what’s on the left side of the arrow, the sufficient condition, is triggered, everything on the left side is triggered. It’s like the domino effect.

How to identify the conditional statements? Look for keywords.

Key words for sufficient condition are : If, when, whenever, where, wherever, all, any, each, every, whoever, wherever. The part of the sentence that comes after these keywords is sufficient condition.

Key words for necessary condition are: Only if, only when, then, only where, requires, must, demands, depends on, relies on, The part of the sentence that comes after these keywords is necessary condition.

Let’s draw a few examples of conditional statements. Once I read them, pause the screen and try drawing them by yourself before you see my working.

  1. If you are caught cheating during the test, you will have to attend an extra classes

Caught cheating is sufficient condition because it comes right after keyword “if” and the other part of the sentence is necessary condition.

We will have caught cheating or CC on the left side of the arrow and EXTRA CLASS, EC, on the right side of the arrow

CC → EC

  1. You have no courage if you won’t jump from a mountain

What comes after “if” in this sentence is sufficient condition.

JP → C

  1. Only funny people laugh in the sleep

What comes right after Only is necessary condition because Only is necessary condition keyword. Funny people will come on the right side of the arrow.

S → FP

  1. She can design a house only if she has a pen

Same thing as the previous example. We have a necessary condition keyword “only If”

DH → P

When there is “ If and Only if” in  conditional statements – it means that both statements are necessary and sufficient for each other. We draw a Double-ended arrow for conditional statements with if and only if in them.

Lets look at an example:

Jack will record a course if and only if Ali is recording a course. What does that mean? It means that Ali will not record a course if Jack is not there and Jack will not record a course if Ali is not there. we cannot have one and not the other. 

We will draw it this way:

JRC 🡨 🡪 ARC

Contrapositive: Contrapositive of the conditional statement is just an alternative way to express it. There is no logical difference between a conditional statement and its contrapositive.

In a conditional statement, when the necessary condition is denied, the sufficient condition is denied as well.

Example

In contrapositive, the conditional statement is flipped and negated.

A 🡪 B

B 🡪 A

What happens when we have and in a conditional statement? It turns into OR when we take its contrapositive.

And if we have OR in a conditional statement, It turns into AND.

Suppose we have a conditional statement:

A and B 🡪 C

C 🡪 A or B

A or B 🡪 C

C 🡪 A and B

 

 

Sometimes, arguments commit conditional flaws.

There are two kinds of conditional flaws. Flip flaw and negation flaw.

Flip flaw is committed when a conditional statement is flipped but not negated.

Use example

A 🡪B

B 🡪 A

Negation flaw: is committed when both sides of a conditional statements are negated but the conditional statement is not flipped.

Use Example

A 🡪  B

A 🡪  B

Another major concept and a very helpful one is property of conditional statements to be able to to be combined. We can connect conditional statements and form a long chain which may lead to significant inferences.

Let’s say we have three conditional statements:

A 🡪 B

B🡪 C

C 🡪 D

A🡪 D

Prompt

Look for

Eliminate

Must be true/Could be False EXCEPT:

Must be true

Could be false

Could be True/Must Be False EXCEPT:

Could be true

Must be false

Could be False/Must be true EXCEPT:

Could be false

Must be true

Must be false/Could be True EXCEPT:

Must be false

Could be true

LSAT Logical Reasoning Cause and effect

Whenever the author tries to explain why something has happened, you should think about cause and effect relation.

A cause and effect argument states that one thing is causing the other. Typically, premises of an argument will assert correlation between two things and conclusion will claim that one thing causes the other.

These arguments are typically wrong. Just because two things are happening at the same time, does not mean one is causing the other. There could be a third factor causing both or one of them.

Cause and effect arguments are different from conditional statements. It’s important to be able to differentiate them. In conditional statements, occurrence of sufficient condition triggers necessary condition. Whereas in cause and effect arguments, based on correlation between two things, the author infers causation.

Cause and effect statements can be identified by the keywords such as: due to, caused by, resulting from, as a result, because of, stems from, produced by, induced by, contribute to.

Strength of the language

Strength of language matters in the logical reasoning section because conclusion can only be supported by the premise of equal or greater strength.

Let me help you visualize it:

Let’s say we have a ceiling supported by 3 pillars.

What happens if the ceiling is heavier than the strength of the pillars? It will fall, right?

Same thing will happen in a logical reasoning question. If premises,the pillars, are weaker than the conclusion, the ceiling, things fall apart.

There are two parts of language strength:

One has to do with probability and the other with proportion.

The probability is how likely something will happen

 

Strong: Must, will, always.

moderate: Probably, likely, Usually.

Very weak: May, Might, could, can.

 

Words that indicate proportion

Strong: Anyone, every, all. Which means 100%

Moderate: Most, majority, >50%

Weak: Some, many, few, several 0-100%

Must Be true

  1. In Must be true questions, Right answer choice must be entirely true based on the information given in the stimulus. There will be information in the stimulus that fully proves the right answer.
  2. The four wrong answer choices might have some support from the stimulus but will not be fully proven true. To prove one of them, you will have to bring outside information or make some assumptions, which you are not allowed to.
  3. If there are conditional statements in the stimulus, draw them and combine them and Expect an answer choice that is proven by combination or contrapositive of the conditional statements.
  4. We cannot predict anything in must be true questions because it is an information-based question type.
  5. I highly recommend you to read the stimulus carefully.
  6. After reading the stimulus, just move to answer choices and look for the one that is proven entirely true by the stimulus.
  7. Lastly, Answer choices are often incorrect because they are too strong. Be cautious with words such as “all” “most”. If the answer choice has them, make sure stimulus supports them.

Most Strongly supported

  1. In Most strongly supported questions, the right answer does not have to be fully proven true by the stimulus, like in the case of must be true questions.
  2. Most strongly supported questions are similar to must be true questions but there is one  difference. Right answer in must be true has to be 100% true but right answer in most strongly supported doesn’t have to be. It just need to receive little bit of support from the stimulus.
  3. The four wrong answer choices won’t receive any support at all
  4. Expect a weak answer choice in this question.
  5. If there are conditional statements in the stimulus, draw them and combine them and expect an answer choice that is combination or contrapositive of the conditional statements.
  6. I highly recommend you to read the stimulus carefully.

Must Be False:

    1. The right answer choice must be proven completely false by the stimulus.
    2. An answer choice that could be true in some situations based on the information in the stimulus is a wrong answer choice.
    3. If there are conditional statements, draw them and combine them and expect an answer choice that is inconsistent with the statements or their contrapositives.

     

    Quantifier

    Definition

    Percentage

    All

    Everyone

    100%

    Most

    More than half

    >50%

    Some

    At least one

    >0%

    None

    Not any

    0%

Method of Reasoning:

  1. Our task in the method of reasoning questions is to describe the structure of the argument. Basically, the questions ask us what was author’s method of reasoning, how does author make their point, how does author get to the conclusion
  2. And so, it is important to Identify conclusion in the argument.
  3. And then, see how the argument reaches the conclusion. How does the author navigate through the premises and get to the conclusion.
  4. Does the author attack the opposite side to make their point, or does the author offer alternative explanation of a situation to support their conclusion.
  5. It is not an easy question but by zooming out, and looking at the stimulus in the bigger picture, you can identify the method of reasoning.

Explain questions

In Explain questions, there is an issue in the argument that needs to be explained.

Our task is not to resolve the issue but just explain its cause. Why is it happening? Which is very different from trying to come up with a solution to the issue, the task we have in resolve or paradox questions.

Before going to answer choices, try to predict information that could explain the issue.

LSAT Logical Reasoning Role

In the role question, we have to identify the role of a sentence in the stimulus.

  1. A not so effective strategy is to read the stimulus and see how that sentence fits in the whole argument. It saves time but it’s not the best way to go about it.
  2. Here’s the strategy that we have developed.
  3. First step is to Identify the conclusion in the stimulus.
  4. Second step is to identify the sentence mentioned in the question.
  5. Third step is to see how that sentence is related to the conclusion
  6. It could be the conclusion itself, Or, a premise that supports the conclusion , or, a secondary conclusion that supports the conclusion or information against the conclusion).
  7. Basically, the role of a sentence in an argument is how it is related to the conclusion. Rather than looking at how it fits in the whole argument, we just focus on how it is related to the conclusion.

Parallel Reasoning

  1. In Parallel Reasoning questions, we have to find an answer choice whose structure matches with that of the stimulus.
  2. Read the stimulus and extract its structure and then go to answer choices and extract their structures.
  3. Choose the answer choice that has the same structure. 
  4. Pay attention to the argument’s strength of language because the right answer needs to match that also.
  5. The order of premises and the conclusion in the right answer choice does not have to match.
  6. Be careful of answer choices that have the same subject matter or same wording as the stimulus, they are typically trap wrong answer choices.
  7. If you see conditional statements in the stimulus, draw them.

Flaw questions

  1. The right answer choice has to describe flaw in the argument.
  2. First step is to identify the conclusion in the argument.
  3. Since it is a flaw question, we know with certainty that there is  a flaw in the stimulus.
  4. It exists right between the premises and the conclusion.
  5. You should try to predict the flaw before you go to answer choices.
  6. Once you have found the conclusion, Ask yourself, “why is the conclusion not justified based on the premises.
  7. With the right evidence, we can justify anything.
  8. The problem in the flaw question is that evidence, the premises, is insufficient to justify the conclusion and that’s where the flaw is.

There are some flaw types which are more common than the other. Let’s go through all of them.

Sampling flaw

In the LSAT Logical Reasoning, samples and surveys rarely justify an argument. If the stimulus does not say that the sample is true representative of the population, be a bit critical about it. In the flaw questions, samples are almost always not the representative of the group it is given to represent.

The right answer choice will say something along the lines of:

The argument makes a generalization on the basis of a sample that is unlikely to be representative of the population.

In the LSAT, a conclusion is not justified just because the majority of the group believes in it.

Right answer will say: The argument defends a claim solely on the grounds that most people believe in it.

Composition flaw

Just because the group as a whole has certain characteristic, does not mean that each member also has that characteristic.

For example, if a team of football players is best in the tournament, it doesnt mean that each player of the team is also good. There might be some players who are not good at all.

Also, just because each member of a group has a certain characteristic, it does not mean that each member of the group has that characteristic.

For example, a team might comprise the best football players in the world but it still might not be the best performing team for various reasons.

Conditional flaws

We might have to deal with two conditional flaws that we have already discussed: flip flaw and negation flaw

An argument commits Flip flaw when it just flip the conditional statements without negating them.

A 🡪B

B  🡪 A

The right answer choice will say:

The argument mistakes something that is necessary to bring about a situation with something that in itself is enough to bring about the situation.

An argument commits Negation flaw when it just negates the conditional statements without flipping them.

A 🡪 B

A 🡪 B

 

The right answer choice will say:

The argument confuses being an adequate solution with being a required solution. The argument takes a condition that is sufficient for the conclusion to be true as one that is necessary for the conclusion to be true.

Causation flaw

We know that correlation does not mean causation. Just because two things are happening at the same time, it does not mean that one is causing the other.

If an argument concludes causation based on corelation, its a flawed argument.

The right answer choice could do one of the following:

  • Expose the flaw.
  • Suggest alternative cause for one or both effects.
  • Reverse the Cause and effect.

The right answer choice will say something like:

The argument fails to exclude an obvious alternative explanation for the observed effect.

The argument concludes merely from the fact that two things are correlated, that one causes the other.

Comparison flaw

When an argument compares two things which are different in many ways, it commits a comparison flaw.

Just because two things have a property in common, does not mean they must have one or more properties in common.

The right answer choice will say something like:

The argument ignores major differences between two things.

The argument infers that since two things are similar in one respect, they must be similar in other respect.

 

Ad Hominem flaw

In Ad hominem flaw, the author criticizes a person rather than that person’s argument.

To refute an argument, it is necessary to provide evidence against the argument. Any negative information against the author has no impact on the argument in the LSAT.

For example:

Let’s say a politician has been found guilty of corruption multiple times, it’s still not sufficient to disregard his policy recommendations. Even if a politician has lost credibility, it does not mean the politician’s policy recommendation is a bad one. Furthermore, a politician might recommend a policy which she does not support in her constituency. Just because she acts inconsistently to her own recommendations, it does not mean recommendation is not a good one.

The right answer choice can say:

The argument attacks the person making the argument rather than the substance of the argument.

The argument rejects a claim simply because of the motivation that some people have for making it.

Lack of evidence flaw

No one has been able to prove the existence of aliens, but does that mean they don’t exist? No.

Nor, has anybody been able to prove that aliens don’t exist, but does that mean they do exist? No.

Just because there is lack of evidence to prove an argument, it does not mean that the argument is entirely wrong.

Or, Just because there is lack of evidence to disprove an argument, it does not mean that the argument is entirely correct.

The right answer choice will say something like:

The argument concludes that a claim is false merely on the grounds that the evidence for it is insufficient.

The argument assumes that a proposition is true because it has not been proven false..

Circular reasoning flaw

When an argument’s conclusion repeats one or more of its premises, we have a circular flaw.

The right answer choice might say:

The argument’s conclusion is identical to one of its premises.

Predictive flaw

Predicting the future based on the past or making conclusions about the past based on the present does not work in the LSAT. The circumstances might have changed or will change which will prevent something from repeating.

This is not an exhaustive list of flaws. There are many which are not in the list but they are not as frequent.

Predicting flaws in your own words is the best way to tackle flaw questions.

The purpose of going through this list was to help you learn common flaws so that you can quickly identify them on the test day if they occur in the argument.

Parallel Flaw:

In parallel flaw questions, we have to find an answer choice that commits exactly the same flaw committed in the stimulus.

  1. Identify the flaw in the stimulus just the way you would do in flaw questions.
  2. Identify flaws in the answer choices.
  3. Some of the answer choices might not have any flaw.
  4. Right answer choice will have exactly the same
  5. The logical structure of the argument doesnt need to match as it had to in parallel reasoning questions.
  6. Lastly, Do not go to the Answer choices until you have identified the Flaw in the Stimulus.

Weaken Questions:

The right answer choice must weaken the conclusion. It does not have to destory the conclusion. Slight damage will do the job. The four wrong answers will not weaken the conclusion at all.

At Access Prep, we have devised a very effective strategy for weaken questions.

Start with identifying the conclusion in the stimulus.

Second step is to take the soft opposite of the conclusion

For example, if the conclusion is “The Government has been very successful at decreasing the unemployment rate.” Soft opposite of this statement will be “The government  hasn’t necessarily been successful at decreasing the unemployment rate.” That “necessary” is the key word in our technique. After taking the soft opposite, look for the answer choice that supports the soft opposite.

One might wonder why don’t we just look for an answer choice that weakens the conclusion rather than taking its soft opposite and then looking for an answer choice that supports the soft opposite.

At Access Prep, we have tried both strategies on countless weaken questions, and we found that the soft opposite technique is way more effective.

In weaken questions, right answer choice will show that even if the premises are true the conclusion does not have to be true based on them.

Try to see what is wrong with the argument because sometimes there is flaw in the argument and right answer choice exposes it.

Furthermore, The qualifier “if true” in the question tells you not to be concerned about the validity of the answer choices. Instead, you should consider the impact they have on the answer choices.

Basically, do not cross out an answer choice just because it has new information. Mostly, the right answer choice has new information that weakens the conclusion.

Things get a bit complicated when we have cause and effect argument in weaken question:

If the author concludes causation based on correlation between two things,  it is a cause-and-effect argument and there are three ways to weaken it. But before I share those three ways with you, just know that you can tackle a cause and effect argument with the soft opposite technique. In fact, cause and effect arguments are not so common in weaken questions. Hence , you do not have to worry about them.

Three ways to weaken cause and effect argument.

  1. Same Cause no Effect: We do have the cause, but we do not have the effect.
  2. No Cause but same Effect: We do not have the cause, but we do have the effect.
  3. Alternative Cause: It can bring an Alternative Cause.

Only one answer choice will say one of these things, not more than that.

Lets there’s a fish farm near a toys factory. One day, the farmer notices that fish are dying. She also notices that a chemical is leaking from the factory into the farm. Based on this, she concludes that its the chemical killing the fish.

This is a typical cause and effect argument. Based on the information that two things are happening at the same time, the author concludes that one is causing the other.

Let’s weaken it:

Same Cause no Effect: Let’s say there is another farm nearby in which we don’t see fish dying but the same chemical is leaking in it also.

No Cause but same Effect: Let’s say there is another farm nearby in which we see fish dying but we don’t see any chemical leaking in it.

Alternative Cause: There might be an answer choice that says that something else has changed in the region that could potentially affect the fish health. Things such as weather etc.

How to answer a weaken question if the word “except” appears in it?

“Each of the following weakens the argument EXCEPT.”

The right answer does not have to strengthen the argument. If it’s irrelevant, it’s the right answer choice. As long as it does not weaken the argument.

Strengthen

  1. In strengthen question, the right answer choice must strengthen the conclusion. It must increase the chn=ances that the conclusion is true. It doesn’t have to guarantee it.
  2. First step is to identify the conclusion.
  3. Predict what right answer can say to increase the chances that the conclusion is true
  4. Go to the answer choices
  5. If there is a flaw or weakness in the argument, the right answer will try to cover it. Its just like representing a client in a court. You want to cover weaknesses of her case and expose weaknesses of the opposition.
  6. The incorrect answer choice will either weaken or be irrelevant.

If it’s a cause-and-effect argument, just like in weaken questions, there are 3 ways to strengthen cause and effect arguments.

  1. Same Cause same Effect: We do have the cause, and we have the effect.
  2. No Cause no Effect: We do not have the cause, and we do not have the effect.
  3. Ruling out alternative Cause: Ruling out alternative Cause.

Let’s go back to that fish farm example:

We have a fish farm near a toys factory. One day, the farmer notices that fish are dying. She also notices that a chemical is leaking from the factory into the farm. Based on this, she concludes that it’s the chemical killing the fish.

There are three ways to strengthen it:

  1. Same Cause same Effect: Let’s say there is another farm nearby in which we see fish dying and the same chemical is leaking in it also.
  2. No Cause no Effect: Let’s say there is another farm nearby in which we don’t see fish dying but we don’t see any chemical leaking in it.
  3. Rule out Alternative Cause: There might be an answer choice that says that nothing else has changed in the region that could potentially affect the fish health. Things such as weather etc.

People confuse sufficient and necessary assumptions a lot. Let me make it clear: They are very different question types. We cannot put them in one category: assumption questions.

Sufficient Assumptions are usually strongly worded (e.g. all mostly) while Necessary Assumptions are weakly worded (e.g. some, few, maybe).

Sufficient assumption we make to help author. We create it to prove the conclusion.

In necessary assumption, our task is to identify an assumption that the author has already made. It already exists. We just have to identify it.

0-100% scale

Sufficient Assumption

“Which of the following, if assumed, would allow the conclusion to be properly drawn?”

“The argument above can be logically drawn, if which one of the following is assumed?”

The key to identifying sufficient assumption question stems are the phrases “logically follows” and “properly drawn.”

Right answer choice must prove that the conclusion is true. If there is any shadow of a doubt where it doesn’t make the conclusion 100% true, eliminate it.

Identify the conclusion.

Identify any gap between the premises and the conclusion.

Predict what we could add to the argument to guarantee the conclusion.

Answer choice acts as a bridge between the premises and the conclusion. It fills the gap to justify the conclusion 100%. Adding it to stimulus leaves no gap between premises and conclusion.

Wrong answer choices might support the conclusion but will not guarantee it.

Sufficient Assumption is a premise which you pick from the answer choices and put it in the stimulus, and it makes the conclusion super strong.

Answer could be stronger that what is needed to prove the conclusion. But it cannot be weaker than what is required.

Necessary Assumption

“Which one of the following is an assumption on which the argument depends?”

“Which one of the following is an assumption on which the argument requires?”

“The argument relies on which one of the following assumptions?”

  1. It is something you must have for conclusion to be valid, if you take it away, conclusion will be weakened, and argument will fall apart. (0-100% example)
  2. Necessary assumption is necessary condition for the conclusion.
  3. Think of it as a conditional statement
  4. CT→NA
  5. NA→CT
  6. If the necessary assumption is negated, the conclusion is not valid anymore.
  7. Employ the negation method to find the right answer choice.
  8. If the right answer choice is negated conclusion is weakened.
  9. If the negation weakens the conclusion, then it is the right choice.
  10. It is usually weak and not always easy to predict because so many things might need to be true for conclusion to be valid
  11. An argument may have more than one necessary assumption.
  12. Of course, only one of them will appear among the answer choices.
  13. It is the minimum amount of information needed to be true for the conclusion.
  14. Tends to be weaker than what is needed to prove the conclusion

Conditions: Conditional Statements vs. Assumptions

Suf/Nec conditions are different from suf/nec assumptions

Necessary/sufficient assumption exist with the relation to the conclusion; hence, its only limited with the conclusion while the conditional statements could be premises or conclusion

Agree

  1. Identify the conclusions of the arguments of both authors.
  2. Try best to predict the point of agreement between both authors

Avoid answer choices which one or both speakers do not have an opinion on.

Disagree

  1. Identify the conclusions of the arguments of both authors.
  2. Try best to predict the point of disagreement between both authors.
  3. Avoid answer choices which one or both speakers do not have an opinion on.

Resolve/Paradox/Reconcile

  1. Mostly, this question type is not an argument and so there won’t be a conclusion. But when it has a conclusion, you must focus on it.
  2. There is an issue in the stimulus that the right answer choice attempts to resolve.
  3. Typically, the issue/paradox has two sides. We have to solve the issue without picking either side.

LSAT Logical Reasoning Main point

LSAT Logical Reasoning Main point of a question is its main conclusion. Find the conclusion of the argument that way we do in all argument-based questions. The right answer will say something that is close to the conclusion of the argument. You won’t have to summarize the whole stimulus. `

Use the 3 ways to identify the conclusion. Conclusion of the of the argument is the main point or main conclusion. We do not have to summarize the whole argument. The right answer choice will be word to word or slight variation of the sentence you identify as the conclusion in the argument.

  1. Look for the key words (therefore, thus, hence, it follows that).
  2. Look for words that sounds like opinion (should, must, ought to be).
  3. Look for sentences in the stimulus that is supported by all the sentences. But it does not support anything.
  4. Main conclusion does not have to be at the end.
  5. Subsidiary conclusion: it is a conclusion that supports the main conclusion. It has its own premises but is itself is used as a premise to support itself.
  6. LSAT will never give you two correct answers, there will always be something to make it incorrect (look for it!).
  7. Look for the point that the argument as a whole is trying to establish.
  8. The incorrect answer choices often restate a premise or part of a premise.
  9. If there is a “hence” or “therefore” in a statement, do not assume that it’s the main conclusion of the argument. It could be a secondary conclusion.

sidiary conclusion.

  1. This is a question type in which you can predict with certainty.

Evaluate

What does it mean to evaluate?

When we evaluate something, we are assessing it, judging it. That is exactly what we do in the evaluate questions. We judge the validity of an argument in evaluate questions.

  1. Typically, the answer choices are questions. Task is to find the answer choice, a question that, once answered, will give us information that will either strengthen or weaken the argument. It probably sounds complicated. It will make more sense as I solve evaluate questions.
  2. First step is to identify the conclusion in the stimulus.
  3. Then go to the answer choices and look for one that will either strengthen or weaken the argument.
  4. The four wrong answer choices will have no impact on the argument.
  5. Evaluate The Argument questions are rare on the logical reasoning section of the test.

Words That Indicate Quantity

None

0%

Some

1%-100%

Most

51%-100%

Not All

0%-99%

All

100%

Principle Questions

Principles are like general rules.

There are three types of LSAT Logical Reasoning principle questions:

  1. Type I: Principle is in the stimulus.
  2. Type II: Principle is in the answer choice.
  3. Type III: Principle is in the answer choice.

Type I: Which one of the following conforms most closely to the principle illustrated above?

  1. Principle is in the stimulus.
  2. The answer choices present specific scenarios.
  3. Right answer choice has a scenario that conforms to the principle in the stimulus.

Type II: The reasoning above most closely conforms to which one of the following principles?

  1. Principle is in the answer choices.
  2. The stimulus has a specific scenario.
  3. Right answer choice has a principle to which the given scenario will conform.

Type III: Which of the following principles, if valid, most helps to justify the mayor’s reasoning?

  1. Principle is in the answer choices.
  2. The stimulus has a specific scenario.
  3. Right answer choice has a principle that justifies the given scenario.

Type III is the most common type. Type I is second-most common, and Type II is least common, in fact rare.

Type III is It is like sufficient assumption question because the principle must guarantee the conclusion. Since you have already covered sufficient questions, principle questions will be relatively easy for you.

The difference between Type II and Type III is that the principle in the Type III must justify the argument. Pay attention to wording in Type II and Type III question stems. Type II uses word “conforms” and Type III uses word “justify”. This one-word difference changes the task in the question.

Parallel Flaw:

In parallel flaw of LSAT Logical Reasoning questions, we have to find an answer choice that commits exactly the same flaw committed in the stimulus.

Strategy:

  1. Identify the flaw in the stimulus just the way you would do in flaw questions.
  2. Identify flaws in the answer choices.
  3. Some of the answer choices might not have any flaw.
  4. Right answer choice will have exactly the same
  5. The logical structure of the argument doesn’t need to match as it had to in parallel reasoning questions.
  6. Lastly, do not go to the answer choices until you have identified the Flaw in the Stimulus.

Complete the Argument

In this question type, its crucial to identify the pattern of reasoning right before the blank. What comes in the blank is almost entirely directed by what comes 1-2 sentences right before it. For example, what will most likely come in a blank in following situations: 1 2 3 _ 4 8 12 _ X Y _ If you noticed the pattern of the information before the blank, your answers should have been 4, 16 and Z. Similarly, you have to observe pattern of reasoning right before the blank. To find right answer choice faster, spend few seconds predicting answer, even in very general terms. Sometimes, these questions are a lot like Main Point questions. The difference is, this time you are predicting main point of the argument rather than identifying in the stimulus. Basically, you have to fill the blank with the main point of the argument. There will be a conclusion keyword (hence, therefore, thus etc.) at the beginning of the sentence and a blank to fill at the end of that sentence. As always in this question type, you have to pay attention to the direction of the argument right before the blank. Some samples: “Therefore, __________.” “Hence, in the new century, the stability of a nation’s cultural identity will likely __________.” “Thus, in many cases, by criminals’ characterization of their situations, __________.  Logical Reasoning Sample QS

Table of Contents

[Next Read: T14 Law Schools: A Complete Guide]

Logo-03

SHOP NOW. PAY LATER.

Learn More

Sitemap

Social Media

Youtube

Copyright © 2024 Access Prep LLC. All Rights Reserved.

Logo-03

4 Interest-Free Payments.

See payment terms. A higher initial payment may be required for some consumers. CA residents: Loans made or arranged pursuant to a California Financing Law license.

  • Contact Info

  • About Yourself