Mary’s LSAT Morning-Of Cheat Sheet


iStock_000014937781SmallYou aren’t allowed to take into the LSAT a cheat sheet of key rules, but what if you were? I made one for you.

Don’t sneak it in (not that you could—my bike map was confiscated), but maybe give it a read the morning of, or print out a copy to review at stoplights on the way there.

Better yet, use the idea as inspiration to make your own. Remember when as a kid you’d be assigned flashcards, and you thought the point was the set of cards, itself, when really it was making the cards that taught you the material (clever teachers!)? Creating your own one-pager can be a great study tool during the final few days before the test.
Here’s mine:

1. On matching questions, principle questions, and assumption family questions, be sure to characterize the conclusion of the argument you’re trying to match, find a principle to support, or analyze. I boil conclusion characterization down to two categories: room for doubt, and no room for doubt. “Room for doubt” conclusions rely on terms like: may, could, likely, probably, possibly. “No room for doubt” conclusions rely on stronger language: will, must, should, is, does. The right answer choice will respond correctly to the type of conclusion you’re dealing with.

2. On weaken and strengthen questions, be suspicious of terms in the answer choice that make it vague: some, sometimes, often, many. (Because remember, “many” just means “some,” and “some” just means “more than one.”) Also be wary of any answer choice that could “go either way”—that in one interpretation strengthens, but in another arguably valid interpretation, could weaken.

3. Only, the only, and only if. Only dogs bark = It barks only if it’s a dog = The only thing that barks is a dog = If it barks, it’s a dog. All are diagrammed: B –> D

4. Unless is “if not.” Don’t go unless I tell you to = If I don’t tell you to, don’t go, i.e. ~Tell you –> ~Go

5. If you can’t find the gap, look for one-sided terms. Every question in the assumption family of questions has a gap between the premise(s) and the conclusion. If you can’t find what that gap is, look for a term that appears on one side of the arrow but not the other—that is, a term that appears in a PREMISE but not in the CONCLUSION, or vice versa. These are like signposts pointing you to the gap.

6. The God Rule. If something hasn’t yet been proven, that doesn’t mean it’s false. It just means it hasn’t been proven yet.

7. The Spinning Wheels Rule. If the wheels of your brain are spinning and it’s been two minutes, it’s time to move on. Make an educated guess, and if you have time, come back to it.

8. On the “which rule if substituted for X rule would have the same effect on the game” question, ask yourself: (1) How would I diagram this new rule? (2) What inferences would I make based on it? (3) Does the diagram of the new rule and inferences match the diagram of the old rule that I’m replacing? If not, knock it out.

9. The Ol’ On-Off Switch v. Dimmer Trick. If an argument is an on-off switch argument—something is or is not true, something will or will not happen, people do or do not do something—then be suspicious of answer choices that place people and things on a spectrum (like a dimmer): something is more or less true, something is more likely or less likely to happen, or people are more or less inclined to do something. These are unlikely to match the argument.

10. When in doubt, don’t choose “circular reasoning.” If the flaw is “circular reasoning,” it should be fairly obvious, because the conclusion will say the same thing as one of the premises. For example, “Annie’s hair is curly and red, therefore Annie has curly red hair.” Sound unfamiliar? Right, because it doesn’t appear on the test very often, so when in doubt, don’t choose it.

Good luck, and remember to eat protein for breakfast!

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