LSATLogical Reasoning: Parallel Structure

Question Type: Parallel Structure
These questions ask you to match up two arguments that share structural characteristics.
There are usually two parallel structure questions in each Logical Reasoning section. They
are usually in the second half of the section, and they can usually be recognized by their
length since each answer choice is a complete argument. Sometimes the stimulus argument
is flawed. In such a case, you must identify the answer choice argument that shares
the same flaw.

NOTE
These questions can use up a disproportionate amount of time. We recommend that you only attempt thisquestion type on test day if you have successfully tackled all or almost all the other questions within the section.

Some sample question stems are
1. Which one of the following arguments is most similar in its reasoning to the
argument above?
2. The flawed reasoning in which one of the following arguments most closely
resembles the flawed reasoning in the professor’s argument?
3. The reasoning in the argument above most closely parallels that in which one of
the following?
4. The flawed pattern of reasoning in the argument above is most similar to that in
which one of the following?
5. Which one of the following contains questionable reasoning most similar to that
in the argument above?
6. The pattern of reasoning in which of the following is most similar to that in the
mayor’s argument?
Strategies
One way to approach the parallel structure questions is to reason by analogy. In other
words, if you match up the analogous parts, the structure becomes clearer. The structure
of the argument is more important than the content or subject matter of the argument.
Do not be fooled by answer choices that refer to the same subject matter as that
presented in the stimulus argument. You are expected to see past the facts presented and
look at the relationship between the evidence and conclusion in the argument.
Sample Parallel Structure Question
Consider the following example:
1. Murcheson’s drawing of the Lincoln Monument contains several inaccuracies.
Therefore, your attempt to reproduce the drawing of the monument will not be a
very accurate reproduction of the drawing.
Which one of the following is most similar in its flawed reasoning to the flawed
reasoning in the argument above?
(A) Katrina’s presentation was made up primarily of fabrications and distortions.
So the video recording made of it cannot be of good quality.
(B) An architect who creates a model of an ugly building must necessarily create
an ugly model, unless the sculpture is a distorted representation of the
building.
(C) If a puppy’s coloring resembles its mother’s, then if the mother’s fur is curly,
the puppy’s fur must also be curly.
(D) Kelly imitated Rory. But, Kelly is different from Rory, so Kelly could not
have imitated Rory very well.
(E) Quentin’s second movie is similar to his first. Therefore, his second movie
must be entertaining since his first movie won many awards.

The best answer is A. The flaw in the stimulus argument is that it concludes that a
reproduction of a flawed reproduction cannot, itself, be an accurate reproduction.
Answer choice A makes the same mistake. In this instance, Murcheson’s drawing and
Katrina’s presentation fill the same role as one another in their respective arguments.
And, video recording of Katrina’s presentation is analogous to the attempted reproduction
in the stimulus argument. Some of the other answer choices are also flawed arguments;
however, they do not share the same structure.