In the following questions we will discuss the form of the stimulus and answer
choices against the background of our discussion so far. Please take a moment
to complete the following problem:
1. Carl is clearly an incompetent detective. He has
solved a smaller percentage of the cases assigned to
him in the last 3 years—only 1 out of 25—than any
other detective on the police force.
Which one of the following, if true, most seriously
weakens the argument above?
(A) Because the police chief regards Carl as the
most capable detective, she assigns him only
the most difficult cases, ones that others have
failed to solve.
(B) Before he became a detective, Carl was a
neighborhood police officer and was highly
respected by the residents of the
neighborhood he patrolled.
(C) Detectives on the police force on which Carl
serves are provided with extensive resources,
including the use of a large computer
database, to help them solve crimes.
(D) Carl was previously a detective in a police
department in another city, and in the 4 years
he spent there, he solved only 1 out of 30
crimes.
(E) Many of the officers in the police department in
which Carl serves were hired or promoted
within the last 5 years.
The form of this problem—that a low success rate must indicate a bad performance—
has appeared on several different LSATs.
Prephrasing isoften easier with Weaken questions than with some other question
types. Simply put, many people are good at attacking a position and prephrasing puts
that skill to use.
This was the first question on one of the Logical Reasoning sections of the
December 2003 LSAT, and provided a nice way to start the section. Law
Services classifies this as an easy question, but as a starting point for our
discussion that is helpful. The structure of the argument is simple, and it is easy
to see why the premise does not undeniably prove the conclusion. The answers
contain several predictable forms, and this is the type of question you should
quickly destroy. You do not need to spend a great deal of time trying to find a
specific prephrased answer because there are so many possibilities, and the
answers can be eliminated without a great deal of time spent considering which
are Losers and which are Contenders.
The stimulus uses a premise about success rate to form a conclusion about
Carl’s competency as a detective. Ask yourself—does the premise prove the
conclusion? No, because there are many factors that could have affected Carl’s
performance. In this sense, the stimulus has incomplete information, and we
should try to discover a relevant piece of information in one of the answer
choices that will shed more light on why Carl’s success rate is so low. Use this
knowledge to make a general prephrase that indicates you are looking for a
piece of information that shows Carl’s success rate is not as low as it seems or
that other factors limited Carl’s performance.
Answer choice (A): This is the correct answer. We discover that Carl receives
the hardest cases, and one would expect that the hardest cases would yield a
lower success rate. Notice that this answer does not attack the premises. Even
though they are still true, the conclusion is undermined by the new evidence.
This is typical of most Weaken questions answers—the premises are not
addressed and the focus is on the conclusion.
Answer choice (B): This answer is irrelevant. It tries to use the opinion of others
about Carl’s performance in one capacity to refute facts about his performance
in another capacity. Personalize the answer—is this the answer you would offer
to weaken the argument against Carl if he was your friend?
Answer choice (C): This is an Opposite answer that strengthens the claim that
Carl is incompetent by showing that Carl was not deprived of certain resources
for solving cases.
Answer choice (D): This is another Opposite answer that strengthens the claim
that Carl is incompetent. This time, the answer shows that Carl has a previous
record of poor performance.
Answer choice (E): This answer goes beyond the scope of the argument by
discussing the promotions of other officers. These promotions do not impact
Carl’s job and no information is given about Carl’s promotions. If you are
thinking that perhaps Carl’s poor performance is a result of dissatisfaction over
the promotions of others, then you are assuming too much.
Now we will move to a somewhat harder question. Please take a moment to
complete the following problem:
2. Beverage company representative: The plastic rings that hold six-packs of beverage cans together pose a threat to wild animals, which often become entangled in the discarded rings and suffocate as a result. Following our lead, all beverage companies will soon use only those rings consisting of a new plastic that disintegrates after only three days’ exposure to
sunlight. Once we all complete the switchover from the old to the new plastic rings, therefore, the threat of suffocation that plastic rings pose to wild animals will be eliminated.
Which one of the following, if true, most seriously
weakens the representative’s argument?
(A) The switchover to the new plastic rings will
take at least two more years to complete.
(B) After the beverage companies have switched
over to the new plastic rings, a substantial
number of the old plastic rings will persist
in most aquatic and woodland environments.
(C) The new plastic rings are slightly less
expensive than the old rings.
(D) The new plastic rings rarely disintegrate
during shipping of beverage six-packs
because most trucks that transport canned
beverages protect their cargo from sunlight.
(E) The new plastic rings disintegrate into
substances that are harmful to aquatic
animals when ingested in substantial
quantities by them.
In two-speaker stimuli where you are asked to weaken the argument of one
of the speakers, the test makers often use misdirection and place an answer
choice that weakens the argument of the other speaker.
The conclusion of this argument is the final sentence, which contains the
conclusion indicator “therefore,” and the conclusion contains a qualification that
the threat of suffocation will be eliminated after the switchover is complete. The
premises supporting this conclusion are that the new plastic rings will be used
by all companies and that the rings disintegrate after three days’ exposure to
sunlight. Personalize this argument and ask yourself—are there any holes in this
argument? Yes, there are several. The most obvious is, “What if an animal
becomes entangled in the new rings before they can disintegrate?” In this
question, however, that avenue of attack is not used (this was a two-question
stimuli and that idea was used in the other question) but there is no way to
know this prior to attempting the question.
Answer choice (A): This answer does not hurt the argument because the author
qualified the conclusion to account for the date of the switchover, thereby
inoculating against this avenue of attack. From a personalizing standpoint,
imagine what would happen if you raised this issue to the beverage company
representative—he or she would simply say, “Yes, that may be the case, but I
noted in my conclusion that the program would be effective once the switchover
is complete.” This is an attractive answer because it raises a point that would be
a difficult public relations issue to address. Regardless, this does not hurt the
argument given by the beverage company representative, and that is the task at
hand.
Answer choice (B): This is the correct answer. Answer choice (E)
is only attractive if you make a mistakenly broad interpretation of the conclusion.
Answer choice (E) is a great place for the test makers to place an attractive
wrong answer because (E) is the last answer that a student will read, and the
contents of (E) “reverberate” in the test taker’s mind and begin to sound
reasonable. In that same vein, answer choice (A) is a great place to put the
correct answer if the stimulus is exceedingly difficult to understand or if
the question stem is extremely unusual. Why?
Because most test takers use the first answer choice in a difficult problem
to get a handle on what they are reading and the type of answers
they will see. If a problem is tough, it can be difficult to immediately
identify answer choice (A) as correct. Then, by the time they have read
all five answers, they are prone to have forgotten the details of the
first answer choice.
Most people select answer choice (E), but as you will see, (E) is incorrect.
This answer undermines the representative’s conclusion by showing that even after the switchover is complete, the threat to animals from plastic rings will persist. Note the carefully worded nature of the conclusion—the representative does not say the threat
from new plastic rings will be eliminated, but rather the threat from plastic rings,
which includes both old and new rings.
Answer choice (C): This out-of-scope answer addresses an issue that is
irrelevant to the representative’s argument.
Answer choice (D): While this is nice information from a customer service
standpoint (you do not want your six-pack of beer falling apart as you walk out
of the store), this answer does not affect the conclusion because it does not
address the threat of suffocation to animals.
Answer choice (E): This is the most commonly chosen answer, and it is a
perfect example of a Shell Game. In this case, the answer preys upon test takers
who fail to heed Primary Objective #4: “Read closely and know precisely what
the author said. Do not generalize!” Many test takers read the conclusion and
think, “So when they start using these new rings, it will make things better for
the animals.” When these test takers get to answer choice (E), the answer looks
extremely attractive because it indicates that the implementation of the new
rings will also have a harmful effect. With this thinking in mind, many test
takers select answer choice (E) thinking it undermines the conclusion and they
are certain they have nailed the question. However, the conclusion is
specifically about suffocation, and answer choice (E) does not address
suffocation. Instead, answer choice (E) is a shell game that attacks a conclusion
that is similar but different than the actual conclusion. Remember, one of the
rules for weakening arguments is to focus on the conclusion, and knowing the
details of the conclusion is part of that focus.
Finally, the placement of answer choice (E) is no accident. Most students do not
immediately identify answer choice (B) as the correct answer, and even those
that keep it as a Contender often feel it could be stronger. Then, just when
things are starting to look bleak, answer choice (E) pops up sounding fairly
reasonable. Most people breathe a sigh of relief and select the answer without
carefully examining the contents. Never choose answer choice (E) just because
the first four answers are not overly attractive! Always make a thorough
analysis of every answer choice and remember that the test makers know that
people get nervous if none of the first four answer choices jump out at them. Do
not let the test takers draw you into a trap!
Please take a moment to complete the following problem:
3. There is relatively little room for growth in the overall carpet market, which is tied to the size of the population. Most who purchase carpet do so only once or twice, first in their twenties or thirties, and then perhaps again in their fifties or sixties. Thus as the population ages, companies producing carpet will be able to gain market share in the carpet market only through purchasing competitors, and not through more aggressive marketing.
Which one of the following, if true, casts the most
doubt on the conclusion above?
(A) Most of the major carpet producers market
other floor coverings as well.
(B) Most established carpet producers market
several different brand names and varieties,
and there is no remaining niche in the
market for new brands to fill.
(C) Two of the three mergers in the industry’s last
ten years led to a decline in profits and
revenues for the newly merged companies.
(D) Price reductions, achieved by cost-cutting in
production, by some of the dominant firms
in the carpet market are causing other
producers to leave the market altogether.
(E) The carpet market is unlike most markets in
that consumers are becoming increasingly
resistant to new patterns and styles.
This is another difficult problem but very typical of the LSAT. As always, the
key to success is to isolate the conclusion, which appears in the last sentence:
“companies producing carpet will be able to gain market share in the carpet
market only through purchasing competitors.” As you should have noted while
reading, the conclusion contains a conditional indicator and is thereby
conditional in nature. The conclusion can be diagrammed as:
GMS = gain market share in the carpet market
PC = purchasing competitors
GMS-----------> PC
According to the author, to gain market share in the carpet market a company
must purchase a competitor. Answer choice (C) is often selected by students,
but it does not attack this idea. To attack a conditional statement you must show
that the necessary condition is not actually necessary for the sufficient condition
to occur. Answer choice (C) simply suggests that when companies purchase
their competitors the endeavor is often financially unsuccessful. Essentially,
answer choice (C) fails to prove that purchasing competitors is unnecessary to
gain market share. Answer choice (D), on the other hand, does suggest a way
for companies to gain market share without purchasing competitors, thereby
attacking the conditional statement given in the stimulus. Thus, answer choice
(D) is correct.
Answer choice (A): This answer goes beyond the scope of the argument, which
is limited to the carpet market (and not other floor coverings).
Answer choice (B): This is an Opposite answer that strengthens the argument.
If there are no remaining niches to fill, then there is no way to expand other than
to purchase a competitor.
Answer choice (C): This attractive answer is wrong for two very strong
reasons:
1. A Shell Game is played with the details of the conclusion. The
conclusion is about market share. Answer choice (C) is about a
decline in profits and revenues. The two are not the same, and so the
information in the answer choice does not weaken the conclusion.
2. Even if you assume that market share is the same thing as profits and
revenues, a second Shell Game is played because the answer then
attacks a conclusion that is similar but different than the given
conclusion.
If the conclusion were as follows:
PC-----------> GMS
then answer choice (C) would be correct (again, assuming market
share is the same thing as profits and revenues). But, the above is a
Mistaken Reversal of the conclusion, and so the attack is made on a
statement that uses the same terms as the conclusion but puts them in
a different relationship. This is a great example of the cleverness
displayed by the test makers. Fortunately you can avoid this answer if
you know what to look for when attacking conditional reasoning.
More on this topic in the next section.
One point worth noting is that it is no accident that the most tempting wrong
answer choice appears just before the correct answer. This is a classic LSAT
trick, and one that is very effective because most test takers relax once they find
an answer they feel is attractive. This makes them less likely to closely examine
the answers that follow. Never relax during the LSAT!
Answer choice (D): This is the correct answer. If price reductions drive out
some of the carpet producers, then other producers can take the market share
left behind. This scenario shows that a company can gain market share without
purchasing a competitor, thus attacking the necessary condition in the
conclusion.
Answer choice (E): This Opposite answer strengthens the argument. If the
consumers are resistant to new styles, then one fewer possibility exists if a
company is trying to increase market share. By eliminating this option, the
conclusion is strengthened (if you eliminate an idea that would hurt the
argument, that strengthens the argument because it has fewer “competitors.”
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