Weaken Questions
Key Takeaways
- A weaken answer makes the author's support less persuasive; it does not have to disprove the conclusion.
- Most weaken answers attack the gap by showing an alternate cause, relevant difference, bad sample, failed condition, or measurement problem.
- The credited answer is assumed true, so the issue is its logical effect, not whether it is realistic or pleasant.
- Wrong weaken answers often attack the topic, a premise that is accepted for the question, or a weaker conclusion than the author actually made.
What Weakening Means
A weaken answer hurts the argument. It does not have to show the conclusion is false. It only has to make the conclusion less well supported by the stated premises. This distinction is crucial because many correct weaken answers leave the conclusion possible.
LSAC tells test takers to work within the information given. On weaken questions, that means accepting the stimulus facts and adding the answer choice as true. Do not argue with the premise unless the answer shows that the premise is being misused or measured in a misleading way.
Stem Signals
| Stem wording | Task |
|---|---|
| most weakens | damages support the most |
| most seriously undermines | attacks the reasoning's central link |
| casts doubt on | reduces confidence in conclusion |
| calls into question | exposes a vulnerability |
A weakener is not always a contradiction. It may simply make an alternate explanation more plausible or show that the evidence does not apply to the conclusion's target.
Attack The Link
Start by finding the conclusion and the support. Then ask: what would make this support less convincing? If the premise is a study, attack representativeness, controls, measurement, or generalization. If the premise is a comparison, show a relevant difference. If the premise is a plan, show a condition needed for success is absent.
Do not drift into policy debate. If the argument concludes that a new bus lane will reduce commute times, a choice saying the lane is expensive may not weaken unless cost affects implementation or use. A choice saying the road cannot physically accommodate the lane attacks feasibility and is more relevant.
Common Weakener Types
| Argument pattern | Weaken by showing |
|---|---|
| Correlation -> cause | reverse cause, third factor, coincidence |
| Before-after -> cause | another simultaneous change |
| Survey -> population | biased or unrepresentative sample |
| Analogy -> prediction | relevant difference between cases |
| Plan -> result | noncompliance, lack of resources, blocked mechanism |
| Expert -> claim | expertise mismatch, conflict, poor evidence |
| Percent -> amount | denominator changed in the opposite direction |
Most correct weaken answers are local. They do not need to defeat every possible version of the conclusion. They need to undermine this author's reason for accepting it.
Causal Weakening
Causal arguments are the most familiar weaken targets. If the author says A caused B because A and B occurred together, ask what else could explain B. A third factor may cause both. B may cause A. A and B may coincide by chance. A measurement change may make B appear to change.
The best causal weakener often names a concrete alternative explanation. If a school says a new reading app caused higher scores, the strongest weakener may be that the same students also received daily tutoring for the first time. That does not prove the app had no effect. It makes the app explanation less secure.
Generalization Weakening
When the author moves from a sample to a broader group, inspect who was sampled. A study of volunteers may not represent all residents. A poll of people who answer unknown calls may not represent younger voters. A survey of current customers may not represent potential customers.
A weakener can also show the target group is different in a relevant way. If a successful coastal recycling program is used to predict success in a rural county, a relevant difference in population density or collection routes may matter. A difference in logo color probably does not.
Do Not Over-Weaken
Wrong answers sometimes go beyond the conclusion and therefore miss. If the author claims a program will reduce some delays, an answer showing it will not eliminate all delays may not weaken. The conclusion was modest. Match the attack to the claim's force.
A good weakener leaves you less willing to accept the author's inference for the author's stated reason.
Other wrong answers attack a premise that the question expects you to accept. If the stimulus states the survey found a 30 percent increase, a choice saying surveys can sometimes be wrong is usually too general. A choice saying this survey excluded the main affected group is much stronger.
Elimination Tests
- Does the answer affect the conclusion or just the topic?
- Does it attack the support-to-conclusion link?
- Is the conclusion still supported in the same way after adding the answer?
- Is another answer more direct?
- Does the answer accidentally strengthen or explain the author's reasoning?
The most direct weakener usually changes your confidence quickly. If you need several additional assumptions to make an answer hurt the argument, it is probably not best.
Timing And Confidence
Weaken questions reward a skeptical but controlled read. Do not search for every possible objection. Name the argument's main vulnerability and look for an answer that hits it. If a choice is true but unrelated, eliminate it even if it sounds smart.
On test day, remember that the answer is given as true. Your only question is what happens to the argument if this fact is added. If the support becomes less persuasive, keep it. If the support remains intact, remove it.
A reliable weaken process also improves necessary-assumption and flaw work because all three tasks begin with the same gap. The stem decides whether you protect the gap, describe it, or attack it.
Restaurant manager: Food waste fell sharply after we introduced smaller plates. The smaller plates must have reduced waste by encouraging diners to take portions they could finish. Which fact, if true, most weakens the manager's argument?