Lesson 4.5: Evaluate the Argument Questions

Introduction

In this lesson, we’ll focus on evaluating argument questions in the LSAT Logical Reasoning section. By the end of this lesson, students will be able to identify which question would provide the most relevant information for assessing an argument’s validity, apply the variance test, and explain key concepts related to evaluating arguments.

Learning Objectives

• Identify the question whose answer would most help assess the argument.
• Perform the variance test to determine how different answers may change the argument's strength.
• Locate information that is most relevant to evaluating an argument.
• Apply the variance test to confirm the correct evaluation question.
• Understand the main ideas and terminology behind evaluating argument questions.

Evaluating Arguments

To evaluate an argument, it is essential to understand the underlying logic and the assumption being made. An argument typically consists of a conclusion supported by premises. In evaluating an argument, we assess whether the premises adequately support the conclusion and identify any gaps or weaknesses.

Identifying the Evaluation Question

When we encounter an argument, the first step is to identify which question would help evaluate it most effectively. Questions for evaluating arguments often ask us to determine how specific pieces of information can strengthen or weaken the argument. This is a crucial part of the LSAT because the exam frequently tests your ability to unearth assumptions.

Example 1: Consider the following argument:

“Because the neighborhood park has been renovated, local crime rates will decrease.”

In this case, a question that would help evaluate this argument is:

• What evidence supports the claim that a renovated park reduces crime rates?
• Answer: A survey demonstrating reduced crime rates following similar renovations in other neighborhoods would strengthen the connection.

The Variance Test

The variance test is a method used to determine whether changing a specific aspect of the argument would affect the argument's overall strength. Essentially, we ask ourselves: if this premise were altered (or eliminated), would the conclusion still hold?

To apply the variance test, follow these steps:

1. Identify the conclusion of the argument.
2. Examine each premise to see if it is critical to the conclusion.
3. Alter the premise (hypothetically) and assess if the conclusion can still logically be drawn.

Example 2: Let’s use the previous argument again.

• Conclusion: Local crime rates will decrease.
• Premise: The neighborhood park has been renovated.

If we change the premise to “The neighborhood park has been closed,” would the conclusion still hold? The answer is no; the conclusion is weakened.

Hence, this premise is crucial in supporting the argument.

Finding Relevant Information

To evaluate an argument effectively, it is essential to find information that can directly impact the argument's strength. This requires critical thinking and an understanding of the context of the discussion.

Example 3: Consider the argument:

“The rise in online shopping has led to the closure of many local stores, proving that online shopping is harmful to the local economy.”

To evaluate this argument, consider:

• What information would clarify the relationship between online shopping and store closures?
• Data on whether local economies were previously struggling or if other factors contributed to the decline of local businesses would provide important context.

Applying the Variance Test to Confirm Evaluation Questions

After identifying potential evaluation questions, practicing the variance test with those questions will confirm whether they genuinely assist in evaluating the argument. Not every question will be relevant; some may not change the argument’s strength at all.

Example 4: Using our previous argument, let’s evaluate these questions:

1. Would the economy still collapse if online shopping increased due to better delivery systems?
2. Are customers still visiting local shops even as online shopping increases?

The correct evaluation question is the one where changing the premise influences the conclusion significantly.

Applying the variance test:

• Changing the first question leads to a change in our understanding of the argument.
• Changing the second question does not meaningfully affect the conclusion since consumers could shop both online and locally.

Thus, the first question proves more relevant for evaluating the argument.

Conclusion

Understanding how to evaluate an argument is paramount for success on the LSAT. By identifying pertinent evaluation questions and applying the variance test, you can effectively assess arguments and their underlying assumptions. Focus on logical reasoning, ensure clarity in your understanding, and practice frequently to hone your skills in this area.

Study Notes

• An argument consists of a conclusion supported by premises.
• The goal of evaluating an argument is to determine the strength of the premises in supporting the conclusion.
• The variance test helps determine if altering a premise affects the argument’s conclusion.
• Identifying relevant information is crucial for evaluating argument strength.
• Evaluation questions must relate specifically to the impact on the argument’s conclusion.