Solving Parallel Reasoning Questions

Because you must find the answer with a similar pattern of reasoning to that in
the stimulus, using the details of the stimulus to attack the answer choices works
differently in Parallel Reasoning question than in other First Family questions.
For example, The Fact Test plays a minimal role in Parallel questions because
the details (topic, etc.) of the stimulus and each answer choice are different.
Instead, the structural basis of these questions forces you to compare the bigpicture
elements of the argument: intent of the conclusion, force and use of the
premises, the relationship of the premises and the conclusion, and the soundness
of the argument. Comparing these elements is like using an Abstract Fact Test—
you must examine the general features of the argument in the answer choice and
match them to the argument in the stimulus.
First, let us examine the elements of an argument that do not need to be
paralleled in these questions:
1. Topic of the stimulus
In Parallel Reasoning questions, the topic or subject matter in the
stimulus and the answer choices is irrelevant because you are looking
for the argument that has a similar pattern of reasoning. Often, samesubject
answer choices are used to attract the student who fails to focus
on the reasoning in the stimulus. For example, if the topic of the
stimulus is banking, you need not have an answer choice that is also
about banking.
2. The order of presentation of the premises and conclusion in the stimulus
The order of presentation of the premises and conclusion in the stimulus
is also irrelevant. As long as an answer choice contains the same general
parts as the stimulus, they need not be in the same order because the
order of presentation does not affect the logical relationship that
underlies the pieces. So, for example, if the stimulus has an order of
conclusion-premise-premise, you need not have the same order in the
correct answer.
Neither of the elements above has any bearing on the correctness of an answer
choice. Now, let’s look at the elements that must be paralleled, and how to use
these elements to eliminate wrong answer choices:
1. The Method of Reasoning
It may sound obvious, but the type of reasoning used in the stimulus
must be paralleled. When you see an identifiable form of reasoning
present—for example, causal reasoning or conditional reasoning—you
can proceed quickly and look for the answer that matches the form of
the stimulus. Given the numerous forms of reasoning we have examined
(both valid and invalid), you now have a powerful arsenal of knowledge
that you can use to attack these questions. First and foremost, if you
recognize the form of reasoning used in the stimulus, immediately attack
the answers and search for the answer with similar reasoning.
2. The Validity of the Argument
The validity of the reasoning in the correct answer choice must match
the validity of the reasoning in the stimulus.
Often, answer choices can be eliminated because they contain reasoning
that has a different logical force than the stimulus. If the stimulus
contains valid reasoning, eliminate any answer choice that contains
invalid reasoning. If the stimulus contains invalid reasoning, eliminate
any answer choice that contains valid reasoning.
3. The Conclusion
Every Parallel Reasoning stimulus contains an argument and therefore a
conclusion. Because your job is to parallel the argument, you must
parallel the subcomponents, including the premises and conclusion. You
can use this knowledge to attack specific answer choices: if an answer
has a conclusion that does not “match” the conclusion in the stimulus,
then the answer is incorrect. Using this approach is especially helpful if
you do not see an identifiable form of reasoning in the stimulus.
When matching conclusions, you must match the certainty level or
intent of the conclusion in the stimulus, not necessarily the specific
wording of the conclusion. For example, a stimulus conclusion
containing absolutes (“must,” “never,” “always”) will be matched by a
conclusion in the correct answer choice using similar absolutes; a
stimulus conclusion that gives an opinion (“should”) will be matched by
the same idea in the correct answer choice; a conditional conclusion in
the stimulus will be matched by a conditional conclusion in the correct
answer choice, and so on. This knowledge allows you to quickly
narrow down the answer choices to the most likely candidates. This
advice can initially be confusing, so let us discuss it in more detail.
Contenders (assuming there is no other reason to knock them out of
contention). Identical wording for our purposes means answers where
the controlling modifiers (such as “must,” “could,” “many,” “some,”
“never,” etcetera) are the same. For example, if the conclusion of the
argument stated, “The reactor can supply the city power grid,” an
answer that had similar wording, such as “The bank can meet the needs
of customers,” would be a Contender. In brief, the advice in this
paragraph is fairly simple: if the conclusion in the answer choice has
similar wording to the conclusion in the stimulus, then the answer is
possibly correct.
Second, because there are many synonyms available for the test makers
to use, do not eliminate answers just because the wording is not
identical. For example, an answer could state, “The majority of voters
endorsed the amendment.” The quantity indicator in the sentence—
“majority”—has several synonyms, such as “most” and “more than
half.” Make sure that when you examine each sentence that you do not
eliminate an answer that has wording that is functionally identical to the
wording in the stimulus.
Third, remember that the English language has many pairs of natural
opposites, so the presence of a negative term in the stimulus is not
grounds for dismissing the answer when the stimulus has positive
language (and vice versa). For example, a conclusion could state, “The
councilmember must be present at the meeting.” That conclusion could
just as easily have been worded as, “The councilmember must not be
absent from the meeting.” In the same way, an answer choice can use
opposite language (including negatives) but still have a meaning that is
similar to the stimulus.
If the stimulus has a positive conclusion, then the presence of negative
terms in the conclusion is not grounds for eliminating the answer; if the
stimulus has a negative conclusion, then the lack of a negative term in
the conclusion is not grounds for eliminating the answer.
4. The Premises
Like the conclusion, the premises in the correct answer choice must
match the premises in the stimulus, and the same wording rules that
were discussed in The Conclusion section apply to the premises.
Matching premises is a step to take after you have checked the
conclusion, unless you notice that one (or more) of the premises has an
unusual role in the argument. If so, you can immediately look at the
answer choices and compare premises.
Because the four components above must be paralleled in the correct answer
choice, the test makers have an array of options for making an answer incorrect.
They can create answer choices that match several of the elements but not all of
the elements, and to work through each answer choice in traditional fashion can
be a painstaking process. However, since each element must be matched, you
can analyze and attack the answer choices by testing whether the answer choice
under consideration matches certain elements in the stimulus. If not, the answer
is incorrect.
Upon hearing this advice, most students say, “Sounds good. In what order
should I examine at the elements?” Although the process can be reduced to a
step-by-step procedure, a better approach is to realize that examining the
elements is like a waterfall and that everything will happen very quickly.
Performing well on the LSAT is about flexibility and correctly responding to the
clues provided. Rigidly applying the methods below will rob you of the
opportunity to accelerate through the problem. Therefore, in Parallel Reasoning
questions your job is to identify the features of the argument most likely to be
“points of separation”—those features that can be used to divide answers into
Losers and Contenders. Sometimes matching the conclusion will knock out
several answer choices, other times matching the premises will achieve that
same goal. The following list outlines the four tests you can use to evaluate
answers, in rough order of their usefulness:
1. Match the Method of Reasoning
If you identify an obvious form of reasoning (use of analogy, circular
reasoning, conditional reasoning, etc.), move quickly to the answer
choices and look for the answer with an identical form of reasoning.
2. Match the Conclusion
If you cannot identify the form of reasoning, or if you still have two or
more answer choices in contention after matching the reasoning, or if
the conclusion seems to have unusual language, examine the conclusion
of each answer choice and match it against the conclusion in the
stimulus. Matching the conclusion can be a critical time-saver because it
often eliminates one or more answers. On occasion, all five conclusions
in the answer choices will be identical to that in the stimulus. That is not
a problem—it just means that the other elements must be used to knock
out the wrong answers.
The key to successfully matching the conclusion is that you must be
able to quickly pick out the conclusion in each answer choice. This is
where the conclusion identification skills discussed in Chapter Two
come into play.
3. Match the Premises
If matching the method of reasoning and conclusion does not eliminate
the four wrong answer choices, try matching the premises. The more
complex the argument structure in the stimulus, the more likely you will
have to match the premises to arrive at the correct answer. The less
complex the argument, the more likely that matching the conclusion will
be effective.
4. Match the Validity of the Argument
Always make sure to eliminate any answer choice that does not match
the logical force (valid or invalid) of the argument. This test rarely
eliminates all four answers, but it can often eliminate one or two answer
choices.
Now practice applying these elements. Please take a moment to complete the
following problem:

1. If the law punishes littering, then the city has an obligation to provide trash cans. But the law does not punish littering, so the city has no such obligation.
Which one of the following exhibits a flawed pattern
of reasoning most similar to that in the argument
above?
(A) If today is a holiday, then the bakery will not be
open. The bakery is not open for business.
Thus today is a holiday.
(B) Jenny will have lots of balloons at her birthday
party. There are no balloons around yet, so
today is not her birthday.
(C) The new regulations will be successful only if
most of the students adhere to them. Since
most of the students will adhere to those
regulations, the new regulations will be
successful.
(D) In the event that my flight had been late, I
would have missed the committee meeting.
Fortunately, my flight is on time. Therefore, I
will make it to the meeting.
(E) When the law is enforced, some people are
jailed. But no one is in jail. So clearly the law
is not enforced.
As you read the stimulus, you should recognize the conditional reasoning that
pervades this argument. Remember, words such as “if” and “then” are
conditional indicators, and you should pick them up on your LSAT radar and
begin diagramming. In this argument, the first sentence contains a premise, and
the second sentence contains a premise and the conclusion. The sentences are
diagrammed as follows:
LPL = law punishes littering
OTC = city has an obligation to provide trash cans
First sentence: LPL----------> OTC
Second sentence: LPL--------> OTC
The argument is based on a Mistaken Negation. This is an easy form of
argumentation to identify, and you should feel comfortable attempting to parallel
this structure. Therefore, once you recognize a Mistaken Negation and read the
question stem, immediately search for the answer that also contains a Mistaken
Negation.
Answer choice (A): This answer choice contains a Mistaken Reversal.
Answer choice (B): This answer choice contains a contrapositive.
Answer choice (C): This answer choice contains a Mistaken Reversal.
Answer choice (D): This is the correct answer, and the relationship in the
answer can be diagrammed as follows:
FL = flight late
MM = missed the committee meeting
First sentence: FL---------> MM
Second sentence: FL-------> MM
Please note that “my flight is on time” is equivalent to “flight is not late.”
Answer choice (E): This answer choice contains a contrapositive.
This problem shows that if you can identify the reasoning structure in the
argument, that gives you the best opportunity for moving quickly through the
answer choices. If you quickly find the correct answer, you need not worry
about checking conclusions, premises, etc. But sometimes you feel as if you
understand the reasoning very well, but not perfectly. In those cases,
supplement your attack with the other tests mentioned earlier in this chapter.
Please take a moment to complete the following problem:
2. People who are good at playing the game Drackedary are invariably skilled with their hands. Mary is a very competent watchmaker. Therefore, Mary would make a good Drackedary player.
The flawed pattern of reasoning in the argument
above is most similar to that in which one of the
following?
(A) People with long legs make good runners.
Everyone in Daryl’s family has long legs.
Therefore, Daryl would make a good runner.
(B) People who write for a living invariably enjoy
reading. Julie has been a published novelist
for many years. Therefore, Julie enjoys
reading.
(C) All race car drivers have good reflexes. Chris is
a champion table tennis player. Therefore,
Chris would make a good race car driver.
(D) The role of Santa Claus in a shopping mall is
often played by an experienced actor. Erwin
has played Santa Claus in shopping malls for
years. Therefore, Erwin must be an
experienced actor.
(E) Any good skier can learn to ice-skate
eventually. Erica is a world-class skier.
Therefore, Erica could learn to ice-skate in a
day or two.
This problem also contains conditional reasoning (“people who” is a sufficient
condition indicator), but the reasoning structure is not as clean as in the previous
problem. In this argument the first and second sentences contain premises and
the third sentence is the conclusion. We can diagram the argument as follows:
D = good at playing the game Drackedary
SH = skilled with their hands
M = Mary
Premise: D--------> SH
Premise: Mary is a competent watchmaker.
Conclusion: DM
The argument makes the assumption that being a competent watchmaker is
equivalent to being skilled with your hands, and then makes a Mistaken
Reversal using that assumption.
Although this is an understandable form of reasoning, you may have difficulty
quickly applying that form to five answer choices. Given that finding a
duplicate of the reasoning may be time-consuming, how can you speed up the
process? Consider the conclusion for a moment—the controlling element is that
Mary “would make” a good player. That is a fairly specific statement, and one
that must be reasonably matched in the correct answer choice. Thus, let’s see if
we can eliminate a few answer choices by attempting to match the conclusion.
The process is made especially easy because the conclusion appears in the last
sentence of each answer choice, conveniently prefaced by the word “therefore.”
Answer choices (A) and (C) have conclusion components—“would
make”—that are identical to the stimulus, so they both remain as
Contenders.
Answer choice (B) contains a conclusion with no wording similar to
“would make,” so we eliminate this answer for now. We can always
reconsider the answer if none of the others pan out.
Answer choice (D) contains an element—“must”—that is significantly
different than “would make,” so we also eliminate this answer.
Answer choice (E) can be eliminated since the operating element in the
conclusion—“could—is not the same as “would make.”
Thus, by comparing conclusions, three answers have been eliminated in nearly
effortless fashion. Now focus on answer choices (A) and (C) and use the form
of reasoning we identified in the stimulus to determine which answer is correct.
Answer choice (A): This answer contains valid reasoning, and since we are
looking for an answer with flawed reasoning, the difference is sufficient to
eliminate this answer.
Note that the term “family” in this answer is interpreted to include Daryl. If
everyone in Daryl’s family has long legs, then Daryl must also since he is in the
family.
Answer choice (C): Because the other four answer choices have been
eliminated, we can deduce that this is the correct answer. A glance at the
structure of the argument confirms this:
RCD = race car drivers
GR = have good reflexes
C = Chris
Premise: RCD--------> GR
Premise: Chris is a champion table tennis player.
Conclusion: RCDC
This argument equates two different terms (champion table tennis play = great
reflexes) and then makes a Mistaken Reversal, and this is parallel to the
argument in the stimulus.
The lesson to be learned from this problem is that different methods can be used
to eliminate different answers, and the process should be fluid and based on the
signals you derive from the stimulus. This question required a combination of
checking the reasoning, the conclusion, and the validity of the argument. Other
problems will require different combinations. Remember that you have four
basic tests at your disposal, and be prepared to use them when you encounter a
Parallel Reasoning problem.
Also, in case you were wondering, Drackedary is an imaginary game dreamed
up by the jokers at Law Services.
The structure of the stimulus is as follows:
Premise: No one in the French department to which Professor Alban
belongs is allowed to teach more than one introductory level
class in any one term.
Premise: Moreover, the only language classes being taught next term
are advanced ones.
Conclusion: So it is untrue that both of the French classes Professor
Alban will be teaching next term will be introductory level
classes.
First note that the reasoning is valid. If you are uncertain, check the question
stem. Since no mention is made of flawed reasoning, you know that the
reasoning is sound.
Most people find that there is no clearly identifiable (or easily described) form
of reasoning used to draw the conclusion, and each of the answer choices
except (B) contains a conclusion with similar language to the conclusion in the
stimulus. Thus, you must look elsewhere for the factor that separates the answer
choices. Take a moment to consider each premise and how it relates to the
conclusion; the argument is unusual in that both premises independently prove
the conclusion, and this structure must be paralleled in the correct answer.
Now examine each premise:
Premise: No one in the French department to which Professor Alban
belongs is allowed to teach more than one introductory level
class in any one term.
The premise contains two pieces of information: no one in the French
department is allowed to teach more than one introductory level class and
Professor Alban belongs to the French department. Combining those two pieces
yields the conclusion that Professor Alban can teach at most one introductory
level class in a term. This fact is reflected in the language of the conclusion.
Premise: Moreover, the only language classes being taught next term
are advanced ones.
If only advanced language classes are being taught next term, then no person
could teach an introductory level French class next term. That truth is
encompassed in the conclusion when the author states that “it is untrue that both
of the French classes Professor Alban will be teaching next term will be
introductory level classes.”
Turning to the answers, you should look for the answer that has two
independent premises that both prove the conclusion. Because there are two
premises, this “premise test” will take longer to apply and this is one reason we
typically look at the conclusion in a Parallel Reasoning question before
examining the premises.
Answer choice (A): This answer contains a conditional Repeat form, and as
such, the two premises work together. Since the structure of the answer is
different than that of the stimulus, the answer choice is incorrect.
Answer choice (B): Only the first premise in this answer choice proves the
conclusion; the second premise is irrelevant to the conclusion. Therefore, this
answer is incorrect.
As mentioned before, this answer choice is also suspect because the conclusion
is different than that in the stimulus.
Answer choice (C): There are two excellent reasons to eliminate this answer
choice:
1. The answer choice contains invalid reasoning.
2. The two premises work together and are not independent as in the
stimulus.
Answer choice (D): This is the correct answer. As with the argument in the
stimulus, each premise in this answer choice separately supports the conclusion.
Note that as mentioned previously, the negative term in the conclusion of the
answer choice is not a factor that should be considered. For the purposes of
matching the conclusion, “will be” and “will not be” are identical.
Answer choice (E): This answer is very similar to answer choice (A), and
contains a valid form of reasoning based on the Repeat form. Since the two
premises work together and neither proves the conclusion alone, this answer
choice is incorrect.
This problem is more difficult than the previous two problems because you
must go deeper in your analysis of the argument structure to find the point of
separation. If you see that the reasoning is not easy to identify, and the
conclusions in most of the answer choices are similar to the conclusion in the
stimulus, carefully examine the premises as they are likely to be the part of the
argument that will allow you to find the correct answer.
What To Do If All Else Fails
If none of the four tests of analysis reveals the answer, or if nothing stands out
to you when you examine the argument, you can always fall back on describing
the stimulus in abstract terms. Although less precise than the previous tests,
abstracting the stimulus allows for one last shot at the problem.
To abstract the structure of the stimulus, create a short statement that
summarizes the “action” in the argument without referring to the details of the
argument. For example, if the argument states, “The bank teller had spotted a
thief once before, so she was certain she could do it again,” turn that argument
into an abstract description such as “she had done it once, so she knew it could
be done again.” Then, take the abstraction and compare it to each argument.
Does it match your generalized version of the stimulus? If not, the answer is
incorrect. Your description should be a reasonable approximation of what
occurred in the stimulus, but it does not have to be perfect.
In creating the abstraction above, the “it” in the short summary is purposely left
indefinite so that when you attack the answer choices, you can plug in the
“action” to the abstraction and see if it fits. Let’s continue the discussion of the
basic method we can use to solve Parallel Reasoning problems. Please take a
moment to complete the following problem:
4. An independent audit found no indication of tax avoidance on the part of the firm in the firm’s accounts; therefore, no such problem exists. The questionable reasoning in the argument above is most closely paralleled by that in which one of the following?
(A) The plan for the introduction of the new
product has been unmodified so far;
therefore, it will not be modified in the
future.
(B) The overall budget for the projects has been
exceeded by a large amount; therefore, at
least one of the projects has exceeded its
budget by a large amount.
(C) A compilation of the best student essays of the
year includes no essays on current events;
therefore, students have become apathetic
toward current events.
(D) A survey of schools in the district found no
school without a need for building repair;
therefore, the education provided to students
in the district is substandard.
(E) An examination of the index of the book found
no listing for the most prominent critic of the
theory the book advocates; therefore, the
book fails to refer to that critic.
The question above was selected to help you better understand how to create an
abstraction of the argument and apply it to the answer choices. Approach the
question from the following perspective:
Imagine for a moment that when you first read the stimulus you were
completely lost. Nothing in the argument stood out, and although you
recognized the premise and conclusion, you did not feel that either was
notable.
First, take the “action” of the stimulus and turn it into a generalized summary.
Following is the stimulus and then an abstraction of that stimulus:
Stimulus: “An independent audit found no indication of tax
avoidance on the part of the firm in the firm’s accounts;
therefore, no such problem exists.”
Abstraction: “Since they looked and didn’t find anything, it doesn’t
exist.”
Remember, our abstraction does not have to be perfect—it simply needs to be a
reasonable description of what occurred in the stimulus. If we can only
eliminate three of the answer choices by applying the abstraction, then we can
refine our description until one of the remaining answers is eliminated.
Answer choice (A): Does this answer match our short description of the
stimulus? No, this answer is about “no changes from the past translate into no
changes in the future.” There is no element of “searching and not finding.”
Answer choice (B): Again, quickly, does this answer match our short
description of the stimulus? No, this answer is about cost overruns on projects.
Answer choice (C): This answer is superior to answers (A) and (B). The first
lines indicate that essays on current events are missing from a compilation of the
best essays. This knowledge implies a search has taken place and no essay
fitting the description was found. So far, so good. The conclusion, however,
fails to match what we are seeking. Based on the premise in this answer choice,
we need a conclusion that states something to the effect of, “therefore no such
student essay on current events exists.” Instead, we get an entirely different type
of conclusion: “therefore, students have become apathetic toward current
events.” Since this conclusion fails to match our abstract description of the
stimulus, this answer is incorrect.
Answer choice (D): This answer has an element that is similar to the stimulus,
but in the final analysis it fails to match our abstract description. First, just like
the stimulus, the answer contains a search (the “survey”). However, the search
in the stimulus did not turn up anything whereas the search in answer choice
(D) turns up results (“no school without a need” is the same as “every school
has a need”). Most damning, however, is that the conclusion of the answer
choice does not have the same abstract form as the conclusion in the stimulus.
Since the general intent and execution of this answer does not match our
abstraction, this answer is incorrect.
Answer choice (E): This is the correct answer choice. First, let’s revisit our
general description of the stimulus:
“Since they looked and didn’t find anything, it doesn’t exist.”
Now, compare that to the answer choice:
“An examination of the index of the book found no listing for the most
prominent critic of the theory the book advocates; therefore, the book
fails to refer to that critic.”
A search was conducted but no results were found, and on that basis a
conclusion is drawn that no such thing exists. This perfectly matches our
description, and this answer is correct.
Creating an abstract description of the stimulus is just one more weapon in your
arsenal. As with the previous four tests in this section, you should use it when
you feel it is most applicable. Thinking on your feet is important when attacking
any LSAT question, but no more so than with Parallel Reasoning questions.
You have a variety of techniques at your disposal; you just need to logically
think through each stimulus to decide which ones are most applicable.