Prephrasing: why top scorers know the answer before the choices

Top scorers read an LSAT stimulus, stop before the answer choices, and say what the right answer has to do. Then they go find it. Students in the 150s and low 160s read the stimulus, read all five choices, and pick the one that sounds best, which is exactly what the wrong answers are designed for. This guide is the prephrasing method in full, the form it takes for each question structure, and an original eight-question drill set you can run today with a card over the choices.

The reason this works is structural. LSAC writes four wrong answers per question, and the wrong answers are not random; they’re built to attract a reader who has no prediction. One restates a premise as if it were the conclusion. One is true in the world and inert in the argument. One is right in direction and wrong in degree. One attacks a conclusion the author didn’t draw. Each is attractive only to someone evaluating five candidates on vibes. To someone looking for a specific thing, they’re visibly not it.

What a prephrase is, and is not

A prephrase is one line, in plain words, saying what the right answer must do. It is not a guess at the exact wording. On a weaken question about a bakery that credits a sales jump to a new display, the prephrase is “alternative cause for that specific month’s increase,” not “the bakery ran a promotion.” The first is a job description; the second is one of many possible hires.

That distinction matters because the test often attacks a gap from an angle you wouldn’t predict. If your prephrase is a job description, you’ll still recognize the right answer when it arrives from an unexpected direction, because it does the job. If your prephrase is a specific answer, you’ll reject the correct choice for not matching and get talked into a trap that does.

A prephrase is also not a summary. “The author thinks the display caused the increase” is a summary. “Rule out a rival cause for that month” is a prephrase. The first describes what you read. The second describes what you want.

Keep it short.

The form for each structure

Every one of the twelve argument structures has a prephrase with a fixed shape. Learn the shapes and the prephrase stops being a creative act.

Notice that flaw, strengthen, weaken and evaluate share the first step: find the gap. Once you’ve found it, you have the prephrase for all four. On a section with eight such questions, that’s eight gap-findings and no further thought about what you’re looking for.

Why it’s faster, not slower

Students resist prephrasing because it adds a step before the choices. For about the first forty questions it does cost time, five to fifteen seconds each. Then two things happen. The prephrase itself drops to a few seconds because the shapes are automatic. And the answer-choice phase gets much shorter, because you’re scanning for one thing rather than evaluating five. On a typical hard question, a cold reader spends 40 to 60 seconds deliberating among three attractive choices. A prephrased reader spends 15 seconds confirming one and glancing at the others.

The net effect, in our students’ timed sections, is usually a minute or two back per logical reasoning section within three weeks of starting, plus fewer misses. Both come from the same place. You stop reading what you’ve already ruled out.

There’s a second benefit that doesn’t show on a timer. A prephrase makes your misses diagnosable. When you miss a question cold, blind review tells you the right answer and nothing else. When you miss with a prephrase, you can compare: was the prephrase wrong (you misread the argument), was it right but you didn’t recognize the answer that did the job (a recognition problem), or did you skip it under pressure (a discipline problem)? Three different fixes, and you can only tell them apart if there was a prephrase to check.

The drill set

Eight original stimuli follow, with the question stem and no answer choices. That’s the point. Cover this section below the stimuli, write your prephrase for each on paper in one line, then compare to the key. Time yourself; the goal by the end of the week is under ten seconds per prephrase.

1. Studies show that people who keep a written daily schedule report less stress than people who don’t. Therefore, keeping a written schedule reduces stress. Which of the following, if true, most weakens the argument?

2. The new recycling program accepts glass, which the old program did not. Since residents now have a place to put their glass, the amount of glass in the city’s landfill will fall. The argument depends on which of the following assumptions?

3. No one who missed the orientation session received a parking permit. Everyone in the accounting department received a parking permit. Which of the following must be true?

4. Restaurants that offer a children’s menu are more likely to be rated highly by families. The Harbor Grill wants higher ratings from families. So the Harbor Grill should add a children’s menu. Which of the following, if true, most strengthens the argument?

5. The company’s quarterly survey found that employees who work from home two days a week are more productive than those who work in the office every day. Yet the division that moved entirely to remote work last year saw its productivity drop. Which of the following, if true, most helps to resolve the apparent discrepancy?

6. Everyone who passed the certification exam had completed the preparatory course. Marcus completed the preparatory course. Therefore Marcus passed the certification exam. The reasoning in the argument is flawed because it…

7. Any film that wins the festival’s top prize receives national distribution. Films that receive national distribution recoup their production costs. So any film that wins the festival’s top prize is profitable. The conclusion follows logically if which one of the following is assumed?

8. Some historians argue that the bridge was abandoned because the river shifted course. But the river’s course has been stable for three centuries, according to survey maps, and the bridge was abandoned two centuries ago. So the bridge must have been abandoned for another reason. Which of the following most accurately describes the role played in the argument by the claim that the river’s course has been stable for three centuries?

The key

Compare your lines to these. Yours won’t match word for word and shouldn’t. Check whether they describe the same job.

1. Weaken. Gap: correlation to cause, with an obvious third-factor and reverse-causation problem. Prephrase: “People who are already less stressed are the kind who keep schedules,” or “a trait that causes both.” The trap will be an answer about schedules being hard to maintain, which is true and inert.

2. Necessary assumption. Gap: having a place to put glass to being glass actually diverted. Prephrase: “At least some residents will actually use it,” or equivalently “the glass in the landfill was coming from residents who had no other option.” Negate either and the argument dies. The trap is the strong answer: “all residents will recycle their glass,” which the argument does not need.

3. Must be true. Diagram: Missed orientation → No permit, so contrapositive Permit → Attended orientation. Accounting → Permit. Chain: Accounting → Attended orientation. Prephrase: “Everyone in accounting attended the orientation.” The trap is the converse: “everyone who attended got a permit.”

4. Strengthen. Gap: “more likely to be rated highly” (correlation across restaurants) to “adding one will raise Harbor Grill’s ratings” (causation at one restaurant). Prephrase: “Show the menu causes the ratings, or rule out that family-friendly restaurants just happen to offer kids’ menus.” A good answer: restaurants that added a children’s menu saw family ratings rise afterward. The trap: a fact about how popular children’s menus are in general.

5. Resolve the paradox. Two facts: two days remote is more productive than zero; fully remote dropped. Prephrase: “Something about full remote that differs from partial remote,” such as collaboration loss or the two-day group being self-selected high performers. The trap breaks one fact (“the survey was inaccurate”) rather than keeping both.

6. Flaw. Structure: Passed → Course. Marcus has Course. Conclusion: Marcus passed. That’s the converse, treating a necessary condition (the course) as sufficient. Prephrase: “Mistakes a requirement for a guarantee.” The trap describes a different flaw, like “relies on an unrepresentative sample.”

7. Sufficient assumption. Chain: Top prize → Distribution → Recoups costs. Conclusion: Top prize → Profitable. Gap: “recoups costs” to “profitable.” Prephrase: “Any film that recoups its production costs is profitable.” Strong is correct here; you want the bridge that closes the gap completely. The trap is a necessary-sounding weak answer like “some films that recoup costs are profitable.”

8. Role. The stability claim is evidence against the historians’ explanation, which the author then uses to reach the conclusion that the cause was something else. Prephrase: “Premise that undermines the opposing view, supporting the main conclusion.” The trap calls it the main conclusion, or calls it a claim the author rejects. The author relies on it; the author rejects the historians.

How many of your eight described the same job as the key, even in different words? Six or more means the shapes are landing and you should move to timed sections with a card over the choices for the first pass. Fewer means go back to the table and drill the shapes for the structures you missed, untimed, on old sections.

Building the habit

The learning curve is short but has an order. For the first three days, prephrase untimed with the choices covered, write it down, then uncover and find the match. Writing matters; a prephrase you only think is one you’ll skip under pressure.

From day four through about day ten, do one timed section a day, still writing a two- or three-word prephrase in the margin before reading choices. Your section time will be a little slow. It recovers.

From day eleven, stop writing and just say it in your head, but in blind review, write what your prephrase was for every miss and classify the miss: wrong prephrase, right prephrase and didn’t recognize the answer, or skipped it. By the end of week three, students typically report the prephrase arriving before they’ve consciously decided to make one. That’s the point at which the method is doing its work and you can stop thinking about it.

What to do this week

1. Copy the prephrase shape table onto one page and tape it where you drill.
2. Run the eight-question drill set today with the key covered. Score yourself on jobs matched, not wording.
3. For three days, prephrase untimed on old LR sections with a card over the choices, writing every prephrase down.
4. From day four, one timed section a day with a margin prephrase. In blind review, classify every miss as wrong prephrase, missed recognition or skipped.
5. If after two weeks your misses are mostly “wrong prephrase” on the same two structures, those structures need teaching rather than drilling, and that’s what the diagnostic debrief is for.