PrepTest 141 · Section 2 · Question 9 (Weaken)

Step 1 · Pre-Question Guidance · read this first

Question type

Weaken

The one idea it tests

When a change follows a new rule, the rule may not be the cause: the change may have been rolling already, and the rule may only show up where it was rolling.

The basic logic

Find the claimed cause and effect. Look for an answer showing the effect was already underway, or that something else picks where the rule appears and also drives the effect.

Tiny words that decide it

“shows”
“grounds for”
“only”
“already”

Playground logic

Marcus sees that classes that closed their card-swap tables now have fewer card collectors, so he says the tables cause collecting (top bun). His patty is just a pairing in time. Pop it: Ms. Rivera only closed tables in classes where the card craze was already dying, so the drop was coming anyway.

Step 2 · The kid story

The Case of the Vanishing Card Collectors

Marcus pulled out his detective notebook. "Clue one," he said. "Three classes closed their card-swap tables this fall. Clue two: in those classes, way fewer kids collect cards now, and almost no new kids started. Case closed. Swap tables make kids collect cards!" Priya sipped her juice box. "Who decided which tables to close?" "Ms. Rivera," said Marcus. Lulu flipped her clipboard. "Ms. Rivera told me she only closes a swap table after the class is already bored of cards. She waits until most of the binders are gathering dust." Marcus froze. "So the cards were fading first?" "And the table closing just came along for the ride," said Priya. Biscuit sneezed on a holographic dragon card. Nobody wanted it anyway.

Step 3 · Try the model question

Marcus: In the classes where the card-swap tables were closed, far fewer students now collect cards, and very few have started collecting. This gives strong reason to doubt the claim that swap tables do nothing to make students collect cards.

Suppose each choice below were true. Which would most damage Marcus's argument?

Step 4 · The courtroom tale

The Curfew That Came Late

Mr. Whitfield snapped his suspenders. "Your Honor, towns that adopted the new skateboard ordinance saw far fewer skateboard collisions. Clearly the ordinance works!" Opposing counsel, Ms. Delacroix, rose slowly. "Your Honor, I call the town clerk." The clerk explained: "Towns only pass that ordinance after the skate fad has already started fading. Nobody bothers with it while the fad is hot." The judge raised an eyebrow. "So the drop in collisions was already happening, and the ordinance simply followed it?" "Exactly," said Ms. Delacroix. "The rule did not cause the drop. The drop caused the rule." Mr. Whitfield quietly loosened his suspenders. "I may need a new exhibit," he whispered.

Step 5 · Work the real question

Open PrepTest 141, Section 2, Question 9 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write the conclusion in one line: a cause really does push an effect. Note that the evidence is just a pattern where the rule exists and the effect shrinks. Ask what else could explain that pattern. Hunt for an answer showing the shrinking was already underway, or that the rule only appears where the shrinking is happening, so the arrow may run the other way. Skip answers about what happens after people are already hooked, and answers comparing unrelated kinds of rules.