Evaluate
Argument Logic

Master the art of dissecting reasoning, spotting hidden assumptions, and identifying logical flaws in GRE Verbal arguments.

GRE Verbal

What Is an Argument?

On the GRE, an "argument" is not a dispute. It is a structured set of claims in which premises (evidence or reasons) are offered in support of a conclusion (the point the author wants you to accept).

Premise

A fact, observation, or reason the author provides as evidence.

Conclusion

The claim the author wants you to believe based on the premises.

Anatomy of an Argument

Why Evaluating Logic Matters

GRE Verbal questions frequently ask you to strengthen, weaken, or identify the assumption underlying an argument. You cannot answer these without first mapping the argument's logical structure.

Strengthen

Find the choice that supports the assumption or adds evidence.

Weaken

Find the choice that attacks the assumption or provides a counter-explanation.

Identify

Name the hidden assumption the author relies upon.

The Assumption Bridge Principle

To evaluate an argument, ask: "What must be true for this conclusion to hold?" The answer is the assumption. If the assumption fails, the argument fails.

Common Logical Gaps

Causal

Author assumes A caused B, when A and B may just correlate or a third factor C explains both.

Analogy

Author assumes two situations are similar enough that what works for one applies to the other.

Sampling

Author assumes a small or biased sample represents the whole population.

Plan / Proposal

Author assumes a proposed action will achieve its goal without unintended side effects.

Strengthen vs. Weaken

	Strengthen	Weaken
Goal	Support the assumption	Attack the assumption
Causal gap	Rule out alternative causes	Introduce an alternative cause
Analogy gap	Show the cases are similar	Show a key difference
Sampling gap	Confirm sample is representative	Show sample is biased
Plan gap	Show plan is feasible	Show plan has a fatal flaw

Five-Step Evaluation Method

1

Find the conclusion. Look for signal words: "therefore," "thus," "suggests," "must be," "should."

2

Identify the premises. What evidence or reasons does the author give? Underline them.

3

Spot the gap. What logical leap occurs between premises and conclusion? Name the gap type (causal, analogy, sampling, plan).

4

Predict the assumption. Before looking at choices, phrase what must be true (or false) to close the gap.

5

Match and eliminate. Choose the answer that best matches your prediction. Eliminate answers that are irrelevant to the gap.

Worked Example: Causal Gap

"A city installed new LED streetlights on Main Street last year. Since then, crime on Main Street has decreased by 20%. Therefore, the LED streetlights caused the crime reduction."

Worked Example: Analogy Gap

"Company X boosted productivity by 30% after switching to a four-day workweek. Therefore, Company Y should also adopt a four-day workweek to boost its productivity."

Strengthen

"Companies X and Y are in the same industry, with similar workforce sizes and roles."

Weaken

"Company Y's work requires continuous 5-day client coverage, unlike Company X's project-based work."

Worked Example: Sampling Gap

"A survey of 200 customers at a luxury department store found that 85% prefer organic produce. Therefore, the majority of Americans prefer organic produce."

Signal Words Cheat Sheet

Conclusion Signals	Premise Signals	Contrast Signals
therefore	because	however
thus	since	although
consequently	given that	nevertheless
it follows that	due to	on the other hand
suggests that	as evidenced by	despite

The Negation Test

When you need to identify the necessary assumption, use the Negation Test: negate each answer choice. If negating a choice destroys the argument, that choice is the correct assumption.

1

Take an answer choice and negate it (flip it to its opposite).

2

Ask: Does the negated version make the conclusion impossible or absurd?

3

If yes: that choice is the necessary assumption. If no: eliminate it.

Trap Answer Types

Out of Scope

Introduces a topic never mentioned in the argument. Tempting because it sounds smart, but irrelevant to the gap.

Opposite Direction

Strengthens when you need to weaken (or vice versa). Always recheck: does this help or hurt the conclusion?

Too Extreme

Uses absolute language ("always," "never," "all") when the argument only needs a moderate claim.

Right Topic, Wrong Gap

Relates to the argument's subject but addresses a different gap than the one between the actual premises and conclusion.

Common Mistakes

Confusing Premise for Conclusion

Students sometimes attack a stated fact rather than the author's inference. Remember: you can't weaken a fact, only the leap from facts to claims.

Bringing Outside Knowledge

The GRE tests reasoning, not world knowledge. An answer must work based solely on what the argument states.

Ignoring the Specific Conclusion

Two arguments can share the same topic but reach different conclusions. Always match the answer to this argument's specific claim.

Question 1 of 5

"After the town of Millbrook introduced a recycling incentive program last year, the amount of recyclable material collected increased by 40%. Thus, the incentive program was the primary reason for the increase in recycling."

▼ Tap to read passage

Which of the following, if true, most weakens the argument?

The argument makes a causal claim: the incentive program caused the recycling increase. Choice C introduces an alternative cause (a state law), which undermines the claim that the incentive program was the primary reason.

Question 2 of 5

"A study of 150 employees at a tech company found that those who used standing desks reported fewer back problems. Therefore, all office workers would benefit from switching to standing desks."

▼ Tap to read passage

The argument is most vulnerable to criticism because it:

This is a sampling gap. The argument leaps from 150 tech employees to all office workers. Choice B identifies the flaw: the sample may not represent the broader population.

Question 3 of 5

"Greenfield School's test scores improved after it extended the school day by one hour. Therefore, Lakewood School, which is currently underperforming, should also extend its school day to improve test scores."

▼ Tap to read passage

Which of the following is an assumption the argument relies upon?

This is an analogy gap. The author assumes what worked at Greenfield will work at Lakewood. Choice D states this assumption directly. Choice C is too extreme ("the only way").

Question 4 of 5

"City officials plan to reduce traffic congestion by building a new highway bypass around the city center. This plan will significantly reduce commute times for downtown workers."

▼ Tap to read passage

Which of the following, if true, most strengthens the argument?

This is a plan/proposal gap. The assumption is that the bypass will actually divert the traffic causing congestion. Choice A directly supports this by confirming that through-traffic (which the bypass targets) is the main cause of congestion.

Question 5 of 5

"All of the patients in Dr. Reeves's study who took Vitamin D supplements showed improved mood within six weeks. Therefore, Vitamin D supplements are an effective treatment for depression."

▼ Tap to read passage

The argument's reasoning is flawed because it fails to consider which of the following?

Without a control group, we cannot know if the improvement was caused by Vitamin D or by the placebo effect (or natural mood variation over time). Choice C identifies this critical flaw in the study design.

EvaluateArgument Logic

What Is an Argument?

Anatomy of an Argument

Why Evaluating Logic Matters

The Assumption Bridge Principle

Common Logical Gaps

Strengthen vs. Weaken

Five-Step Evaluation Method

Worked Example: Causal Gap

Worked Example: Analogy Gap

Worked Example: Sampling Gap

Signal Words Cheat Sheet

The Negation Test

Trap Answer Types

Common Mistakes

Question 1 of 5

Question 2 of 5

Question 3 of 5

Question 4 of 5

Question 5 of 5

Evaluate
Argument Logic