Hard LSAT Evaluate the Argument Questions Practice Questions

Concept Explanation

LSAT Evaluate the Argument questions require you to identify the specific piece of information that would most help determine the validity or strength of a given conclusion. These questions function by asking you to find a "bridge" or a critical missing link in the reasoning that, depending on the answer, could either significantly strengthen or significantly weaken the author's claim. To solve these, you must apply the Variance Test: if providing opposite answers to an option (e.g., "Yes" vs. "No") produces opposite effects on the argument, that option is the correct choice. This skill is a core component of LSAT Prep, as it tests your ability to spot unstated assumptions and logical gaps. Success on these hard-level items involves distinguishing between information that is merely related to the topic and information that is logically necessary to assess the truth of the conclusion.

Solved Examples

1. The Pesticide Argument: A farmer claims that a new organic pesticide is more effective than traditional chemical sprays because the organic fields had 20% less crop damage this season. To evaluate this, we must know if the organic fields were naturally less prone to pests before the trial.
   1. Identify the conclusion: The organic pesticide is more effective.
   2. Identify the premise: 20% less damage was observed in the organic fields.
   3. Apply the Variance Test: If the organic fields were already 50% less prone to pests (Yes), the pesticide might be useless. If they were equally prone (No), the pesticide is likely effective. This makes the initial pest levels the critical factor.
2. The Corporate Wellness Program: A company implemented a gym membership subsidy, and absenteeism dropped by 10%. The CEO concludes the subsidy caused the drop. To evaluate this, we need to know if other factors changed simultaneously.
   1. Identify the conclusion: The subsidy caused the drop in absenteeism.
   2. Identify the potential flaw: Correlation does not equal causation.
   3. Variance Test: Did the company also implement a strict new attendance policy at the same time? If yes, the gym subsidy might not be the cause. If no, the gym subsidy's role is much more likely.
3. The Rare Bird Discovery: An ornithologist argues that a rare bird species is thriving because sightings have doubled in the last year.
   1. Identify the conclusion: The species population is increasing.
   2. Identify the premise: Sightings have doubled.
   3. Variance Test: Has the number of birdwatchers in the area also doubled? If yes, the increase in sightings is just a result of more observers, not more birds. If no, the population increase is a more plausible explanation.

Practice Questions

1. A local government decided to install high-intensity streetlights in a high-crime neighborhood to reduce nighttime robberies. After six months, the robbery rate fell by 15%. The mayor claims the lights were successful. Which of the following would be most useful to know in evaluating the mayor's claim?

2. Recent data shows that students who use digital tablets for note-taking in law school score higher on average than those who use paper and pen. Therefore, the university should provide tablets to all students to improve overall academic performance. Which of the following must be investigated to evaluate this recommendation?

3. A study found that people who drink three cups of green tea daily have lower cholesterol than those who drink none. The researchers concluded that green tea contains compounds that actively lower cholesterol. To evaluate this, what question should be answered?

4. An electronics manufacturer claims its new battery lasts longer than its competitor's because, in a controlled test, the new battery powered a laptop for 10 hours while the competitor's lasted only 8. Which of the following is most important to know to evaluate the manufacturer's claim?

5. A city council proposes a tax on sugary drinks to combat rising obesity rates, citing a similar tax in a neighboring city that was followed by a 5% decrease in obesity. Which of the following would be most helpful in evaluating the potential success of this proposal?

6. An investment firm claims that its "Green Fund" is a superior investment because it outperformed the S&P 500 index by 4% last year. To evaluate this claim, it would be most useful to determine which of the following?

7. A pharmaceutical company claims its new drug is better at treating migraines than the current leading drug because 80% of patients in their trial reported relief within an hour. What information is most critical to evaluating this claim?

8. A historian argues that the invention of the printing press was the primary cause of the increase in literacy rates in the 15th century. Which of the following would be most useful to know to evaluate this argument?

Answers & Explanations

1. Answer: Whether the robbery rate in similar neighborhoods without new lights also fell by 15% or more. Explanation: If crime fell everywhere, the lights weren't the cause. If it only fell in the lit area, the lights likely worked.
2. Answer: Whether students who already have higher GPAs are more likely to purchase and use digital tablets. Explanation: This addresses a potential "selection bias" where the technology doesn't cause the performance, but rather high performers choose the technology.
3. Answer: Whether green tea drinkers generally engage in more exercise and have healthier diets than non-drinkers. Explanation: This identifies a potential confounding variable that could be the real cause of lower cholesterol.
4. Answer: Whether the two laptops used in the test were identical in power consumption and running the same software. Explanation: If the competitor's laptop used more power, the test was unfair and doesn't prove battery superiority.
5. Answer: Whether the neighboring city also launched a major public health and exercise campaign at the same time the tax was introduced. Explanation: This helps determine if the tax was the actual cause of the obesity decline in the other city.
6. Answer: Whether the "Green Fund" carries a significantly higher level of risk than the average stock in the S&P 500. Explanation: In finance, higher returns are often just a compensation for higher risk, not necessarily "superior" management. This is a common theme in complex reading passages.
7. Answer: What percentage of patients taking the current leading drug in a similar trial reported relief within an hour. Explanation: Without a comparison point, the 80% figure is meaningless for determining if the new drug is "better."
8. Answer: Whether literacy rates were already on a significant upward trend before the printing press was invented. Explanation: If literacy was already rising, the printing press might have been a result of literacy rather than the cause.

Frequently Asked Questions

What is the Variance Test for LSAT Evaluate questions?

The Variance Test requires you to take an answer choice and apply two extreme, opposite possibilities to it. If one extreme strengthens the argument and the other weakens it, the choice is the correct answer.

How do Evaluate questions differ from Strengthen questions?

Strengthen questions ask for information that definitely supports the conclusion, while Evaluate questions ask for information that could either support or undermine it depending on what the data shows.

Are Evaluate the Argument questions common on the LSAT?

They are less frequent than Strengthen or Weaken questions but appear regularly. Mastering them is essential for reaching the 170+ score range due to their logical complexity.

Can I use the AI Question Generator for Evaluate questions?

Yes, using the AI Question Generator allows you to generate specific logical reasoning drills focused on Evaluate the Argument stems to build your proficiency.

What is a common trap in hard Evaluate questions?

A common trap is choosing an answer that is "vaguely helpful" but doesn't actually address the specific logical gap between the premise and the conclusion. Always ensure the answer impacts the core logic.