LSAT Evaluate the Argument Questions

These questions are unique in the LSAT Logical Reasoning section because they don't ask you to make a judgment about an argument—they ask you to identify what you would need to know to make that judgment. Mastering them requires a shift in mindset from being a critic to being an investigator, pinpointing the exact piece of missing evidence that determines logical strength. Success here translates directly to points, as these questions test a fundamental and transferable critical thinking skill.

The Anatomy of an "Evaluate" Question

You can identify an Evaluate the Argument question by its specific phrasing. Look for language like: "The answer to which one of the following questions would be most useful in evaluating the argument?" or "Which one of the following would be most important to know in order to assess the argument?" The core task is always the same: find the piece of information that would help you decide if the conclusion is well-supported. The argument presented will always have a conclusion supported by premises, but there will be a logical gap—an unstated assumption. Your job is to find the question that, when answered, best fills that gap.

Crucially, the correct answer will be a question or a statement about information whose truth-value is unknown. It will focus on a factor that the argument depends upon but does not address. For example, an argument concluding that a new diet is effective because people who followed it lost weight assumes that nothing else caused the weight loss. A key evaluation question would be: "Did the people who followed the diet also change their exercise routines?"

The Strengthen/Weaken Duality

This is the most important conceptual key to these questions. The correct answer will always be a consideration that could either strengthen or weaken the argument, depending on the answer. Think of it as a two-way street or a balance scale. A piece of information that could only strengthen (or only weaken) is not useful for evaluation; it already leans one way.

A strong test for any answer choice is to apply the Resolution Test. For a potential answer, ask yourself two questions: "If the answer to this is YES, does that make the argument more convincing?" and conversely, "If the answer is NO, does that make the argument less convincing?" For the correct choice, one resolution will strengthen and the other will weaken. If both resolutions strengthen or both weaken, the choice is incorrect. The information must be critically relevant to the argument's core assumption.

Strategy: The Resolution Test in Action

Let's apply this strategy to a simplified example. Argument: "Local bakery 'Rise & Shine' has seen a 20% increase in revenue this quarter. Therefore, its recent social media advertising campaign has been successful."

To evaluate this, we need information that could cut both ways. Consider this potential answer choice: "Have there been any changes in the pricing of Rise & Shine's products this quarter?"

Now, apply the Resolution Test:

• Resolution 1 (YES, prices increased): This would severely weaken the argument. The revenue increase could be due solely to higher prices, not more customers from the ad campaign.
• Resolution 2 (NO, prices did not change): This would strengthen the argument. With prices held constant, the revenue increase is more likely due to increased sales volume, which the ad campaign might have driven.

Because the "YES" and "NO" answers push the argument in opposite directions, this is an excellent evaluation question. It identifies a key missing factor—price stability—that must be resolved to judge the argument's soundness.

Navigating and Selecting Answer Choices

When reviewing the five answer choices, systematically apply the Resolution Test. Be wary of common wrong-answer traps:

1. Information that is irrelevant to the argument's logic. The question may be interesting but doesn't touch the link between the premises and conclusion.
2. Information that only strengthens or only weakens. This fails the duality requirement. For instance, "Did any competing bakeries close this quarter?" only weakens (if YES) or is neutral (if NO). It doesn't provide a strengthening resolution.
3. Information that is too broad or vague. The best questions are surgically precise about the argument's specific gap.
4. Information that simply restates a premise. You don't need to evaluate what's already given as evidence.

Your process should be: Identify the conclusion and premises, pinpoint the central assumption, and then look for the choice that directly probes that assumption in a two-sided manner.

Common Pitfalls

Falling for the One-Sided Choice: The most tempting wrong answers often sound highly relevant but only work in one direction. You might think, "Oh, knowing that would definitely weaken it!" But if knowing the opposite wouldn't strengthen it, it's not the tool for evaluation. Always check both sides.

Overcomplicating the Resolution: Sometimes test-takers imagine complex, secondary scenarios for how a "YES" or "NO" might play out. Stick to the most direct, logical implication of the information presented. The test is designed so the primary effect is clear.

Mistaking Evaluation for Assumption: Remember, you are not identifying the argument's assumption. You are identifying the question you would ask to discover whether that assumption is true. The correct answer will be the bridge to testing that assumption.

Getting Lost in Content: The subject matter can be dense (law, science, business). Don't let the topic distract you. Strip the argument down to its core logical structure: These facts, therefore this claim. The evaluation question will always target that "therefore."

Summary

• Evaluate questions ask for the information most useful in determining an argument's strength, not for a final judgment.
• The correct answer will always be a factor that could logically either strengthen or weaken the argument, depending on its resolution.
• Use the Resolution Test on every choice: Ask, "If yes/true, does it help? If no/false, does it hurt?" The right answer will have opposing effects.
• The answer must target the argument's central unstated assumption, the gap between its evidence and its conclusion.
• Avoid choices that are irrelevant, one-sided, too broad, or mere restatements of the premises. Your goal is to find the critical missing data point.