LSAT Parallel Reasoning Questions

Now that we’ve seen an introduction to LSAT Parallel Reasoning Questions, let’s get some practice paraphrasing arguments. Paraphrasing is essential since LSAT Parallel Reasoning questions ask you to compare argument forms instead of analyzing, strengthening or weakening those arguments.

This article is the second in a series of articles that discusses Parallel Reasoning Questions on the LSAT test. The series includes the following articles:

• Parallel Reasoning: an introduction
• LSAT Parallel Reasoning Questions: practice

LSAT Parallel Reasoning Questions

Two key steps in the TestSherpa method for Logical Reasoning are to paraphrase the stimulus and form a prephrase of the right answer. In parallel reasoning, you do these two steps at the same time, since the right answer should look very similar to your paraphrase.

To build a paraphrase of a parallel reasoning question, you want to be formal and abstract. You want to represent the argument as formally as possible to identify its logical structure. You want to be abstract, rather than using the language of the stimulus, so that you come up with a generic pattern you can compare to the answer choices. Consider the following stimulus:

The statewide Trivia Bowl was held last weekend. In order to win the tournament, a contestant must answer three questions correctly. Perla answered three questions correctly, so she must have won the Trivia Bowl.

How would you paraphrase this argument?

You should recognize that the first sentence does not have any bearing on the logic of the argument. Ignore it–it’s just padding. If this were another type of Logical Reasoning question, you might paraphrase the stimulus as:

If win –> three questions; Perla three questions –> Perla win

But since this is a parallel reasoning question, you want to be abstract and generic in your paraphrase. This will help you match it up to the answer choices

A –> B;

B –> A

You might also notice that this argument commits the logical fallacy of affirming the consequent.

The final step is to read and paraphrase the arguments contained in the answer choices. You will compare those paraphrases to the paraphrase of the stimulus argument. The answer choice that most closely matches the stimulus is the correct answer.

Next let’s compare the following answers to the stimulus.

(A) To win the county swim meet, a swimmer needs to win three heats. Dave won the swim meet, so he must have won three heats.

This answer choice tries to sucker you in by using language and subject matter that is similar to the stimulus. Nevertheless, you are not supposed to compare the words the arguments use, you are supposed to compare their logical relationship to each other. If you paraphrased this answer, you would get something like:

A –> B;

A –> B

The first statement matches, but the second doesn’t. In fact, this argument makes sense, and the stimulus affirms the consequent. A good argument can never be parallel to a bad argument. Cross this one off.

(B) Good doctors spend time getting to know their patients as people, not just their medical history. Doctor Smith is a bad doctor, so he must not know his patients on a personal level.

Your paraphrase of this argument might look like this:

A –> B;

not A –> not B

This is a bad argument, but it denies the antecedent. We’re looking for an argument that affirms the consequent.

(C) Dean likes to win tournaments. He enters a new tournament every week, even if he is completely unskilled in the tasks involved. He has even won a few trophies.

The LSAT likes to throw you answers like these sometimes. They make you wonder if you read the choice correctly. This answer has no logic at all; it is just a series of statements. Since there is no argument being made, and has no logic of its own, it cannot be parallel. Don’t even waste your time with a paraphrase.

(D) People who win tournaments are confident. People with confidence are usually successful at work. It must follow then, that people who win tournaments are successful at work.

This is a chain of events argument, not an argument that affirms the consequent. Further, it is a good argument so it cannot be parallel to a flawed argument. Your paraphrase might look like this:

A –> B;

B –> C;

A –> C

Consider the following answer choice:

(E) When a television station is owned by a large conglomerate, it often has to edit it’s news to be favorable to its parent company and all of its related products. The local independent station, channel 5, never runs a bad story about XYZ Industries. It must be owned by XYZ Industries, and incapable of fair reporting.

This answer is longer than the stimulus, uses different language and tone, and even has a couple of extras thrown in, such as “incapable of fair reporting.” But if you paraphrase it, you will see it also affirms the consequent and is thus the right answer:

A –> B;

B –> A

LSAT Parallel Reasoning Questions: Summary Tips

• Parallel reasoning questions ask you to identify arguments with similar logic.
• The right answer is the closest to the structure of the stimulus, but may not be a perfect match.
• Parallel reasoning can take a long time–you’ll read up to six different arguments–so skip it until the end.
• Don’t be fooled by similar subject matter–you are only comparing the logical structure.
• Good arguments can never be parallel to bad arguments.

Now return to our LSAT page to review another lesson.