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The big question types · Lesson 7 of 14

Weaken questions (and how strengthen mirrors them)

After this lesson, you can weaken an argument by attacking the connection between its evidence and its conclusion with 1 of 3 proven methods, then flip that same approach to strengthen it instead.

7 min video, plus notes and 1 practice question below

In this lesson

• Tell what a weaken question actually wants: a shakier argument, not a destroyed one
• Break any argument into conclusion, evidence, and the assumption connecting them
• Use the 3 reliable ways to weaken an argument: alternative explanation, irrelevant evidence, and flawed evidence quality
• Catch the 2 trap answers that pull points from rushed test takers
• See why strengthen questions reuse the exact same 3-part setup, conclusion, evidence, glue, aimed the opposite direction: strengthen wants that same assumption more likely to hold, not less

What a weaken question is actually asking you to do

A weaken question isn't asking you to destroy the argument. It's asking you to make it shaky, like a table with 1 loose screw: it still stands, but it wobbles. Your job is to make the argument less convincing, not to prove it's completely wrong.

The question stem shows up in a few different wordings: "which one of the following, if true, most weakens the argument," "calls into question the reasoning," "undermines the argument," or "casts doubt on the conclusion." They're all doing the same job. Notice the phrase "if true": that's your permission to accept the new answer as 100% real, even if it sounds extreme, as long as it damages the reasoning.

Break the argument into conclusion, evidence, and the glue

Before you touch the answer choices, find 3 things: the conclusion (the claim the argument is trying to prove), the evidence (the reason given for believing it), and the glue (the assumption connecting the evidence to the conclusion). That glue is the weak point, and it's where you strike.

When you see a stem like "which one of the following, if true, most weakens," pause for 2 seconds and ask yourself what the gap is before you even glance at the choices. That short pause keeps 5 shiny wrong answers from hypnotizing you into picking whichever one sounds most negative.

Take this example: you should eat at that restaurant because it has 5 stars on Yelp. Conclusion: you should eat there. Evidence: 5 stars on Yelp. The assumption is that Yelp reviews accurately reflect restaurant quality. Learn that most of those reviews were written by the owner's friends, and the link between evidence and conclusion falls apart.

The 3 reliable ways to weaken an argument

First, an alternative explanation. The argument says one cause explains something, and you show another cause fits just as well. If people who take vitamin C get fewer colds, and the argument concludes vitamin C prevents colds, showing that those same people also sleep more and eat healthier hands you a competing explanation.

Second, irrelevant evidence, where the evidence is technically true but doesn't prove the conclusion, like saying a coffee shop is great because it has free Wi-Fi. That says nothing about the coffee. Third, attacking the quality of the evidence itself: if the argument leans on a study, survey, or poll, check whether the sample was biased or the questions were leading. Before you look at the answers, ask which of these 3 patterns the gap matches: is there another cause, is the evidence irrelevant, or is the study unreliable.

2 traps that catch students who rush

The first trap is a strengthener dressed up as a weakener. It sounds logical, but it actually supports the argument. Ask yourself: does this make the conclusion more or less likely? If it's more likely, it's a trap, not your answer.

The second trap is an off-target answer that attacks something true but irrelevant, like background details that never touch the actual link between evidence and conclusion. The strongest weaken answers don't attack the facts themselves. They attack the connection: sure, that evidence could be true, but it doesn't prove the conclusion.

How strengthen mirrors this exact process

Weaken and strengthen are twins facing opposite directions. On a weaken question, you're poking a hole in the bridge between evidence and conclusion. On a strengthen question, you're patching that same hole. Same structure, opposite goal, and once you understand one, you understand both.

The setup work doesn't change. Find the conclusion, find the evidence, and find the assumption connecting them. The only difference is the direction of your answer: a weaken question wants the choice that makes the assumption less likely to hold, and a strengthen question wants the choice that makes that same assumption more likely to hold.

The short version

• Before you lock in a weaken answer, check how much it dents the assumption, not how dramatic it sounds. If it doesn't touch the glue, it's not your answer, no matter how negative it feels.
• Track your hit rate on naming the conclusion, evidence, and glue before you look at the answers. If you can't name the glue in one phrase, you're not ready to eliminate yet.
• Log which of the 3 attack patterns trips you up most: alternative explanation, irrelevant evidence, or a shaky source. Most people are weak on just one, and that's the one worth drilling.

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