Logical reasoning question types - Evaluate the argument que...

Learning Outcomes

After reading this article you will be able to identify Evaluate the Argument questions in the LSAT Logical Reasoning section, explain their characteristics, and apply efficient methods to select the correct answer. You will also recognize common pitfalls and distinguish these question types from strengthen and weaken questions.

LSAT Syllabus

For LSAT, you are required to understand how to assess arguments and determine what evidence, if true, would have the greatest impact on their validity. When reviewing for Evaluate the Argument questions, ensure you can:

• Recognize evaluate question stems and distinguish them from other types.
• Understand how changing or introducing new evidence may affect an argument.
• Apply the “variability test” to determine which answer choice most directly assesses the argument’s central assumption or flaw.
• Identify common mistakes, such as choosing answers that are merely relevant but do not affect the argument.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which of the following is most likely to be a correct answer in an Evaluate the Argument question?
   1. An option that addresses the argument's main assumption.
   2. An option that simply repeats the conclusion.
   3. An option unrelated to the argument.
   4. An option that introduces an opposing viewpoint on an irrelevant issue.
2. What does the “variability test” refer to in Evaluate the Argument questions?
   1. Testing whether negating an answer choice destroys the argument.
   2. Checking if different answers result in different argument strengths.
   3. Determining which evidence has the strongest emotional appeal.
   4. Selecting the answer choice with the broadest scope.

3. True or false? In an Evaluate question, the correct answer must itself prove or disprove the conclusion.

4. Which answer choice would be LEAST helpful in evaluating the following argument?
   “Eating apples daily improves health. Therefore, everyone should eat apples.”
   a) Whether those who eat apples daily are in better health than those who don’t.
   b) Whether some people are allergic to apples.
   c) Whether apples are more nutritious than other fruits.
   d) Whether studies control for exercise and diet when comparing apple-eaters and non-apple-eaters.

Introduction

Evaluate the Argument questions are a distinct subset in the LSAT Logical Reasoning section. Rather than asking you to directly strengthen or weaken an argument, they challenge you to find what information would be most useful in determining how strong or weak the argument is. Typically, the question asks: “Which one of the following would be most helpful to know in evaluating the argument above?” Success depends on knowing how to spot these questions, understanding how they differ from related types, and using a methodical approach to select the best answer.

Key Term: Evaluate the Argument question
A question that asks what new information would most affect the validity or persuasiveness of the argument—either to strengthen or weaken it.

Key Term: Variability test
A method for evaluate questions: If one answer makes the argument stronger and the other weaker, it directly affects the conclusion and is likely correct.

THE ROLE OF EVIDENCE IN EVALUATE THE ARGUMENT QUESTIONS

Evaluate questions focus on the effect that new evidence would have on an argument’s outcome. Unlike strengthen or weaken questions, you are not asked to make the argument better or worse directly, but to identify what information would allow you to judge the argument’s strength.

Typical stems include:

• “Which of the following would be most useful to know in evaluating the argument?”
• “The answer to which one of the following questions would be most relevant to evaluating the argument?”

It is essential to note that the correct answer points to a missing fact or assumption that controls the direction of the argument. The best answer is the one whose truth or falsity would have the greatest impact—making the argument notably stronger or weaker.

Key Term: Central assumption
An unstated premise that must be true for the argument to hold; in evaluate questions, useful answers test this assumption.

DISTINGUISHING EVALUATE QUESTIONS FROM STRENGTHEN/WEAKEN

Evaluate questions may appear similar to strengthen or weaken questions. The key difference is that evaluate questions are about what evidence would affect the argument—not which new evidence actually does. Do not confuse a fact that strengthens or weakens with a “test”—the correct answer is always something that, depending on its truth, could potentially strengthen or weaken, not one that only goes in one direction.

Worked Example 1.1

Argument:
“Company X switched to remote work, and productivity increased 10% last quarter. Therefore, remote work caused the productivity gain.”

Which one of the following would be most useful to know in evaluating the argument?

A) How many employees Company X hired last quarter.
B) Whether other changes were made in addition to switching to remote work.
C) If competitors also had a productivity increase.
D) How Company X measured productivity before and after the switch.
E) Whether employee satisfaction also rose.

Answer:
B is best. If other changes were made, those could be alternative causes—knowing this lets you judge the argument’s causal claim. D is also helpful but less central.

Revision Tip

Apply the "variability test": For each answer, suppose it being true and then being false. If the argument's strength changes dramatically, you have a strong candidate.

APPLYING THE “VARIABILITY TEST”

The variability test is the core approach for this question type. Take an answer and ask: "If this is true, is the argument strong? If it is false, is the argument weaker?" If the answer lets you directly judge whether the conclusion is plausible, it is likely correct.

Worked Example 1.2

Argument:
“Recent graduates from Law School A have higher employment rates than those from Law School B. Thus, Law School A provides a better career preparation.”

Which would be most useful to know in evaluating the argument?

A) The average GPAs of the two schools' graduates.
B) Whether Law School A's graduates had more prior work experience.
C) If Law School B’s graduates applied to as many jobs as Law School A’s.
D) The types of jobs counted in the employment statistics.
E) Whether Law School A gives more career counseling.

Answer:
D. If Law School A counts part-time or temporary jobs, but Law School B counts only full-time, relevant jobs, the meaning of the comparison changes—knowing the job type is essential to evaluating the argument's validity.

IDENTIFYING AND ELIMINATING DISTRACTORS

Often, some answer choices are factually related but do not allow you to judge the argument’s central issue. The correct answer will always let you discriminate between a weak and strong version of the reasoning.

Exam Warning

Avoid answers that give background or only minor explanations. If an option would always help or hurt the argument no matter what, it is likely a strengthen or weaken—not evaluate—answer.

Key Term: Evidence relevance
In evaluate questions, the most relevant evidence will “divide the cases”—the argument is notably more or less persuasive depending on the answer.

PRACTICE STRATEGY

1. Read the argument and spot the causal or comparative claim.
2. Identify the argument's core assumption or main gap.
3. For each answer, use the variability test: If “yes,” does the argument become strong? If “no,” does it become weak?
4. Eliminate answers that do not directly let you assess or “test” the argument’s main assumption.

Worked Example 1.3

Argument:
“The city implemented a bike-sharing program, and traffic congestion declined. Therefore, the bike-sharing program caused lower congestion.”

Which of the following would be most helpful to know in evaluating the argument?

A) Whether there were any other changes in city transportation policies.
B) How many residents used the bike-sharing program.
C) If the population of the city changed during the program.
D) The cost of bike maintenance for the city.
E) If weather patterns were typical during the study period.

Answer:
A is correct. If other transportation changes occurred, congestion may have dropped for reasons unrelated to the bike-sharing program. Depending on the answer, the argument could be strong or weak; this makes A the best evaluate-the-argument answer.

Summary

Key Point Checklist

This article has covered the following key knowledge points:

• Evaluate the Argument questions ask which evidence would most help you judge the strength of an argument.
• Success requires identifying the argument’s central assumption or causal claim.
• The correct answer allows you to “test” the argument—its truth or falsity changes its strength.
• The “variability test” is the main tool: try both possible answers and see if the argument’s validity shifts.
• Avoid answer choices that are always strengthen/weaken or purely background; these are commonly presented distractors to test your discrimination.

Key Terms and Concepts

• Evaluate the Argument question
• Variability test
• Central assumption
• Evidence relevance