Logical Reasoning · Flaw

PrepTest 137 · Section 4 · Question 21

Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.

Step 1 · Pre-Question Guidance · read this first

Question type

Flaw

The one idea it tests

The arguer says the other side is wrong, then answers a different complaint than the one actually made.

The basic logic

Write down the exact claim being rejected. Then check whether any premise actually speaks to it. If the premises talk about safety or carefulness while the claim was about something moving from one place to another, the arguer never touched the real point. This is a Scope Shift.

Tiny words that decide it

“claims”
“wrong”
“furthermore”

Playground logic

Lulu's claim: Tommy's glitter is drifting into her room through the hall fan. Tommy's top bun says she is wrong, but his patty is only that his glitter is safe and he never sprinkles it in her room. That is a Scope Shift: he answers a question about harm and aim, not the question of drifting.

Step 2 · The kid story

The Glitter Storm

Lulu marched into Tommy's room holding a sparkly sock. "Your glitter is drifting into my room through the hallway fan!" Tommy crossed his arms. "Wrong. My glitter is the safe, non-toxic kind. Nobody has ever shown it hurts kids or pets. Also, I never sprinkle glitter in your room. Ever." Lulu stared at him. Then she wrote on her clipboard. "Tommy, I didn't say your glitter was dangerous. And I didn't say you sprinkled it in my room. I said it's floating through the fan." Tommy opened his mouth. Then closed it. Mr. Whiskers walked by, completely covered in sparkles. Priya, passing in the hall, sipped her juice box. "You answered two questions nobody asked," she said. "The one she asked is still sitting there."

Step 3 · Try the model question

Tommy: Lulu claims that my glitter is drifting into her room through the hallway fan, but she is mistaken. My glitter is the safe, non-toxic kind, and no one has shown that it hurts kids or pets. Also, I never sprinkle glitter in her room.

Which choice best describes the mistake in Tommy's reasoning?

Step 4 · The courtroom tale

The Flour Cloud

A dress shop sued the bakery next door. "Their flour dust drifts through the shared air vent and coats our dresses!" The bakery's lawyer rose. "Nonsense. Our flour is organic. No study has shown it harms anyone. And our bakers never set foot in the dress shop." Mr. Whitfield, for the dress shop, hooked his thumbs in his suspenders. "Your Honor, we never said the flour was harmful. We never said the bakers came over. We said it drifts through the vent. My friend has answered three questions, and none of them is ours." The judge peered over her glasses. "Counsel, would you like to address the vent?" The bakery's lawyer shuffled papers. "Er, may I have a recess?"

Step 5 · Work the real question

Open PrepTest 137, Section 4, Question 21 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Write the opponent's exact claim in a few words. Then list each premise the arguer offers. For each one, ask: does this touch the claim, or a different claim? If none of them answer the actual point, the flaw is a Scope Shift. Choose the answer that names the ignored claim, and be wary of answers describing moves the arguer never made.