LSAT Logical Reasoning › Flaw
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
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.”
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.
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
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.”
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.
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).
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
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.
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
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.
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.
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
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.
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
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.”
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.
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.