Determining the flaw in the argument
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LSAT Logical Reasoning › Determining the flaw in the argument
Advertisement: Coma Cola is the best-tasting cola on the market and we conducted a test using over 1000 cola consumers to prove it. Each consumer was given two identical cups filled with a carbonated beverage from the same fountain. One cup was filled with Coma Cola and the other was filled with unadulterated soda water. Ninety-nine percent of the consumers preferred the Coma Cola. So, Coma Cola is the best tasting cola available.
The advertisement’s reasoning is most vulnerable to criticism on the grounds that it fails to consider whether
The consumers tested had the opportunity to evaluate colas other than Coma Cola.
The consumers tested had the opportunity to evaluate flavored soft drinks other than colas.
Coma Cola is cheaper or more expensive than other colas.
Coma Cola has more or less caffeine than other colas.
Any portion of the population is allergic to any of the ingredients in Coma Cola.
Explanation
The advertisement's claim, that Coma Cola is the best tasting cola, is based on 99% percent of cola consumers choosing it over soda water. The flaw in the experimental setup is that just because a consumer chooses Coma Cola over soda water, it does not mean that she will choose Coma Cola over any other cola, let alone over all other colas.
The correct answer recognizes that, in order to validly make such a claim, one would have to show a preference for Coma Cola over other colas, not over soda water (or even over other flavored soft drinks, as one of the incorrect answer choices indicates).
Students that drink green tea while studying have higher test scores than those that drink soda while studying. Tea manufacturers emphasize that students who reported drinking green tea while preparing for a test achieved consistently higher test scores than those students who reported drinking soda while preparing for the same test. If this claim is true, then if the students who drink soda switched to drinking green tea, their test scores will rise.
The reasoning in this argument is flawed because the argument
ignores the possibility that students who drink green tea may have other characteristics besides their drink preference that yield to higher test scores than those students who prefer to drink soda
accepts the conjecture without challenge that green tea is healthier for students than soda
utilizes an unsupported assumption that soda lowers the IQ of students
fails to consider the cost difference between a cup of green tea and a can of soda
does not provide the precise percentage rise in scores of drinking green tea
Explanation
The author, here, makes the mistake of assuming that drinking green tea raises test scores or that conversely, drinking soda yields lower test scores. Therefore, the author ignores the possibility that there may be other characteristics besides drink preference that determines a test taker’s score. Thus, the correct choice is “ignores the possibility that students who drink green tea may have other characteristics besides their drink preference that yield to higher test scores than those students who prefer to drink soda.”
The statement "all blue birds are birds" is true. Thus, by analogy, the statement "all suspected terrorists are terrorists" is also true.
The reasoning in the argument above is flawed because it fails to recognize that
The relationship between being a blue bird and being a bird is not of the same kind as that between being a suspected terrorist and being a terrorist.
The relationship between being a bird and being a terrorist is not of the same kind as that between being blue and being suspected.
The relationship between being a bird and being suspected is not of the same kind as that between being blue and being a terrorist.
Not all birds are blue.
Not all terrorists are suspected
Explanation
It’s true that all blue birds are certainly birds — blue birds are a subset of the larger set of all birds. But a suspected terrorist may not be a terrorist at all. Just because "blue" and "suspected" are both used as adjectives to modify nouns does not mean that they modify the nouns in the same way.
Sports agent: College athletes should be paid for their efforts; otherwise, there is no incentive for them to stay in college rather than become professionals in their respective sports. After all, college sports are nearly as popular as professional sports nationwide, and billions of dollars are made annually by television stations, athletic conferences, and associations promoting the sports. Yet the student athletes themselves see none of the money as long as they remain students. The way to keep athletes in school is to begin paying them salaries commensurate with what they would receive as professionals.
The reasoning in the sports agent’s argument is most vulnerable to criticism on the grounds that the argument
fails to consider the possibility that many student athletes do not play college sports with the intention of becoming professionals in those sports
bases its conclusion on subjective criteria rather than an objective assessment of the merits of paying student athletes
presumes, without providing justification, that college sports are nearly as popular as professional sports nationwide
uses the key term “professional” in two different senses in various parts of the argument
fails to adequately support the premises in such a manner that the conclusion would follow from those premises
Explanation
The argument creates a false dilemma by assuming that all college athletes plan (and are able) to become professional athletes. The paragraph contains no premise which supports this assumption. The remaining answer choices do not properly identify flaws in the argument’s reasoning.
Cook: Often times when I cook, I find that I can become over-ambitious and prepare multiple dishes at once. As a result, I don’t always pay enough attention to everything that I am preparing and have a tendency to overcook some of my creations. I have heard about a new type of cookware that is designed to prevent overcooking, and am thinking of investing in it so that I can prepare better food.
The cook’s reasoning is flawed because he is:
mistaking correlation for causation.
relying on a sample size that is too narrow.
assuming that a condition precedent has already occurred.
confusing cause and effect.
relying on information that does not have a credible source.
Explanation
The cookware is correlated to reduced overcooking. However, the chef thinks that the cookware will cause his food to no longer be overcooked, when the cause of such overcooking appears to be his inability to focus on a single dish because of his excessive multitasking. Therefore, the chef mistakes the cookware that he is using as being the cause of his food being overcooked.
The correct answer identifies the cause/ correlation error that the chef has made.
Therapists who treat patients for long periods of time develop attachments to the patients. Once such attachments are formed, they are unable to take an objective view of the patients’ symptoms, leading to possible bias and inaccuracy in their diagnoses and treatment. Therefore, to improve the quality of their treatment, patients should switch therapists every three to six months.
The reasoning in the argument is most vulnerable to criticism on the grounds that the argument fails to consider the possibility that
long-term relationships between therapists and patients create benefits in the quality of treatment which outweigh the possible negative consequences of attachments
not every therapist develops a strong attachment to every one of his or her patients
most inaccuracies in diagnosis or treatment do not necessarily prevent the patient from continuing to progress therapeutically
it is more expensive to switch therapists every three to six months than it is to remain with the same therapist for a long period of time
the quality of a patient’s treatment is often determined by the therapist rather than the patient
Explanation
The argument’s conclusion states that patients should switch therapists to improve the quality of their treatment, but fails to indicate that the possible bias and inaccuracy resulting from attachments to patients necessarily leads to lower quality treatment. Hence, it is possible that long-term relationships create benefits which outweigh the negative consequences mentioned. The remaining answer choices are either irrelevant or attack the argument’s premises rather than its reasoning and conclusion.
Computers have finally reached their maximum potential for processing information. For fifty years, computer processing capabilities have steadily improved each year. Although some years saw greater advancements than others, each year saw at least some progress. That pattern was broken last year when computer processing capabilities failed to improve at all.
The argument is most vulnerable to which of the following criticisms?
It assumes, without providing support, that if information processing capabilities fail to improve in a given year, those capabilities cannot improve in the future
It fails to address the possibility that some of the previous fifty years saw no progress in information processing capabilities
It assumes, without providing support, that if information processing capabilities improve in a given year, those capabilities have not reached their maximum potential
It fails to account for the possibility that information processing capabilities improved somewhat over the last year, even though there has been greater improvement in other years
It assumes that computer processing capabilities failed to make any progress over the last year.
Explanation
The argument's primary assertion is that information processing capabilities will not improve in the future (have reached maximum potential). It supports this by claiming that no advancements were made last year, but fails to address why that claim supports the conclusion. That there have been advancements in years past is not enough without an additional premise.
Meteorologist: The average temperature last winter was 30 degrees fahrenheit. That was the lowest average temperature for a winter in 20 years. The average temperature this winter will most likely be warmer than last winter's average temperature.
The reasoning in the argument is most vulnerable to the criticism that it
predicts a future event from past events that may have no relationship to the predicted event
assumes that last winter's average temperature will determine this winter's average temperature
assumes that last winter's average temperature will have no bearing on this winter's average temperature
draws a universal conclusion from information about one event
suggests that the average temperature in a particular winter can predict the temperature on a particular day
Explanation
The meteorologist did not establish a relationship between past temperatures and future temperatures. As a result, the conclusion does not necessarily follow from the information given. To remedy this flaw, the meteorologist would need to establish that past temperatures predict future temperatures.
The two opposing armies, Army 1 and Army 2, are the same in regards to size. Since certain diseases that have recently afflicted Army 1 can be attributed to its crowded conditions in its encampment, such diseases must also afflict Army 2.
The reasoning in the argument is most vulnerable to the criticism that it:
fails to take into account other factors that may have caused disease
fails to indicate whether the average life expectancy is lower in Army 1 than Army 2
presupposes that Army 2 is superior to Army 1
does not distinguish between those diseases that are treatable and those that are not
does not take into account the advent of the germ theory of disease
Explanation
The author comes to the hasty conclusion that two armies that share the same size will share the same problem (here disease) associated with the density of their encampments. The author assumes that no other factor could influence the issue, which is not true; e.g. different sanitation procedures, more or better skilled medical personnel, etc. could also influence the incidence of disease. This failure to take into account other alternative explanations is the correct answer choice, “fails to take into account other factors that may have caused disease.”
Tad and Lilly play together in kindergarten every day. Both children have symptoms of an illness. Tad definitely does not have an illness. Lilly’s illness symptoms are similar to Tad’s symptoms. Since Tad does not have an illness, Lilly does not have an illness.
The reasoning in the argument is flawed because the argument:
Wrongly infers that, because something in one instance has not occurred, it has not occurred in a similar situation.
Makes a general claim where specific facts are needed.
Argues that because something is probably true, it is true.
Does not reason that one infection might be a different kind of illness.
Treats symptoms as facts.
Explanation
The flaw in the argument is that Tad’s situation and Lilly’s situation are the same simply because they play in kindergarten together every day. While the evidence that they play in kindergarten is compelling at first and may lead one to select one of the other false answers, it is flawed because it is not certain. The symptoms, even if similar, could be for something else. The question does not provide us with information concerning other illnesses which might have the same symptoms.