Examkin

Sampling and Survey Flaws

20 soru

Tüm türler20Çoktan seçmeli10Doğru / Yanlış5Eşleştirme5
Soru 1Soru →

City transit official: To assess the public's satisfaction with the newly introduced Rapid Commute bus line, we surveyed commuters waiting at the line's busiest stops during the morning rush hour. Over 90 percent of the respondents indicated that the new bus line is highly convenient and significantly reduces their commute time. Clearly, the residents of this city overwhelmingly find the new Rapid Commute line to be a valuable and convenient addition to our transit system.

Which of the following most accurately describes a flaw in the transit official's reasoning?

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Cevap: It bases a broad generalization about the city's residents on a sample that is inherently biased toward those who already use and benefit from the service.

Cevap

The argument bases a broad generalization about the city's residents on a sample that is inherently biased toward those who already use and benefit from the service.
The argument's conclusion makes a sweeping claim about 'the residents of this city' based entirely on a survey of people who were already waiting at the bus stops of the new line. This is a classic example of an unrepresentative sample (selection bias). People who actively choose to wait for a bus are much more likely to find it convenient than the general public. Those who find it inconvenient likely took a different form of transportation and were entirely excluded from the survey.

Adım Adım Çözüm

1
Identify the main conclusion of the argument.
The conclusion is: 'Clearly, the residents of this city overwhelmingly find the new Rapid Commute line to be a valuable and convenient addition to our transit system.'
Locating the conclusion sets the scope of the argument, showing that the official is making a claim about ALL residents of the city.
2
Identify the premises provided to support this conclusion.
The premise is: Over 90 percent of commuters surveyed at the bus line's busiest stops during rush hour find the line convenient and time-saving.
Understanding the evidence reveals how the author attempts to justify the broad conclusion.
3
Evaluate the relationship between the premises and the conclusion to find the logical gap.
The evidence relies on a survey of people already waiting for the bus. People who do not find the bus convenient or useful are highly unlikely to be waiting at the bus stop.
This reveals a textbook sampling flaw (selection bias). The sample is completely unrepresentative of the broader group (all city residents) being discussed in the conclusion.
4
Select the option that best abstracts this specific vulnerability.
The correct option points out that the argument bases a generalization about a larger group on a biased, unrepresentative sample of users.
This perfectly matches the identified logical gap in the argument.

Anahtar Kavram

Identifying Unrepresentative Samples and Selection Bias
Soru 2Soru →

Match each of the following flawed arguments (Left) with the abstract logical description of its specific sampling or survey error (Right).

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Öğeler

To gauge citywide support for a new nighttime noise ordinance, the city council surveyed residents who attended a 2:00 PM Wednesday town hall meeting. Finding that 85% supported the measure, the council concluded that a vast majority of the city's population favors the ordinance.
A productivity app developer sought to prove their tool increases daily output. They sent an in-app questionnaire asking, 'How much has our app helped you achieve your goals this week?' and concluded from the overwhelmingly positive responses that the app objectively boosts productivity.
An historian analyzed the structural integrity of 18th-century wooden ships by examining the five vessels from that era currently preserved in maritime museums. Because all five exhibit exceptional craftsmanship, the historian concluded that 18th-century shipbuilders universally maintained extremely high structural standards.
A restaurant chain implemented a new QR-code feedback system on their receipts. After a month, 90% of the submitted reviews were heavily critical of the service speed. Management concluded that nearly all of their customers are dissatisfied with the speed of service.

Eşleşmeler

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Cevap

The town hall survey matches the temporal exclusion flaw; the app survey matches the presuppositional phrasing flaw; the historian matches the survival subset flaw; and the restaurant matches the self-selection flaw.
Each argument commits a distinct sampling or survey flaw. The town hall argument surveys people at a highly restrictive time, excluding a massive demographic. The app developer uses a leading question that forces a positive premise. The historian looks only at surviving artifacts, which inherently misrepresents the average quality of all artifacts originally produced. Finally, the restaurant relies on a voluntary feedback mechanism, which disproportionately attracts dissatisfied customers.

Adım Adım Çözüm

1
Analyze the town hall scenario to identify its specific flaw.
The sample was taken at 2:00 PM on a Wednesday, excluding those who work standard hours.
This matches the abstract description of generalizing based on a sample that systematically excludes individuals unavailable at a specific time.
2
Analyze the app developer scenario.
The survey asks 'How much has our app helped,' forcing a positive framework.
This matches the abstract description of relying on survey responses elicited by phrasing that presupposes the truth of the conclusion.
3
Analyze the historian scenario.
The historian evaluates only ships that survived hundreds of years in museums.
This matches the description of basing a judgment on a subset that possesses a characteristic merely by virtue of enduring to the present (survivorship bias).
4
Analyze the restaurant scenario.
The data comes from a voluntary QR-code system where customers must choose to leave feedback.
This matches the description of taking for granted that individuals who self-select to participate are representative of the broader population.

Anahtar Kavram

Sampling and Survey Flaws
Soru 3Soru →

Review the following four scenarios, each containing a distinct methodological error related to data collection. Pair each scenario with the corresponding logical flaw description.

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Öğeler

A researcher evaluating a long-term diet program surveyed individuals who have strictly adhered to the diet for five years. Because nearly all of them reported improved cardiovascular health, the researcher concluded that the diet is guaranteed to improve the health of anyone who attempts it.
A technology blogger posted a poll on her website asking whether people prefer traditional laptops or tablets. With most respondents favoring tablets, she concluded that the general public now strongly prefers tablets over traditional laptops.
During the first hour of a citywide festival, a food vendor noticed that the first four customers to visit her stall requested vegan options. She quickly deduced that the vast majority of festival attendees this year must follow a vegan diet.
A university administration surveyed students, asking, 'Do you agree that the university should implement the proposed tuition increase to maintain our prestigious academic facilities?' Because a majority agreed, the administration claimed students fully support the tuition hike.

Eşleşmeler

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Cevap

The correct pairings match the diet program to survivorship bias (failing to account for dropouts), the tech blog to voluntary response bias (self-selected participants), the food vendor to small sample size (insufficient number of cases), and the university survey to leading questions (phrased to elicit a specific response).
Each scenario demonstrates a distinct violation of valid sampling principles. The diet study ignores attrition (survivorship bias). The tech poll relies on a non-random, self-selected internet audience (voluntary response bias). The vendor makes a broad claim based on four data points (small sample size). The university uses loaded language to skew results (leading question).

Adım Adım Çözüm

1
Evaluate the diet program scenario.
Identifies that measuring only those who 'strictly adhered' for five years creates a biased sample of survivors.
Failing to account for participants who dropped out invalidates the claim that the diet works for 'anyone'.
2
Evaluate the technology blogger scenario.
Identifies that a website poll relies on individuals who voluntarily choose to participate.
Self-selected respondents to a niche blog cannot reliably represent the general population.
3
Evaluate the food vendor scenario.
Identifies that a conclusion about the 'vast majority' is based on just four people.
An insufficiently small number of cases cannot support a sweeping generalization about a large group.
4
Evaluate the university administration scenario.
Identifies that the survey question justifies the fee hike by linking it to 'prestigious academic facilities'.
Phrasing an inquiry to elicit a specific positive response invalidates the survey results as objective evidence.

Anahtar Kavram

Identifying and differentiating common methodological flaws in sampling and surveys, including survivorship bias, voluntary response bias, unrepresentative sample sizes, and leading questions.
Soru 4Soru →

Consumer advocate: A recent survey of readers of the magazine *Luxury Auto Weekly* asked whether they prioritize fuel efficiency or engine performance when purchasing a new vehicle. Over 70 percent of respondents indicated that engine performance is their primary consideration. Therefore, automakers should focus less on fuel efficiency, since it is clear that most car buyers prioritize engine performance.

Which of the following most accurately describes a flaw in the consumer advocate's reasoning?

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Cevap: bases a generalization about a large population on a subgroup that is highly unlikely to be representative of that population

Cevap

The argument is flawed because it generalizes about all car buyers based on a highly unrepresentative sample (readers of a luxury auto magazine).
The correct answer accurately targets the argument's use of an unrepresentative sample. The consumer advocate attempts to draw a broad conclusion about the preferences of all car buyers. However, the evidence is derived entirely from a survey of individuals who read 'Luxury Auto Weekly'. It is highly probable that consumers who read a magazine dedicated to luxury automobiles care significantly more about engine performance than the average, everyday car buyer does. Because the sample is skewed, it cannot reliably support a generalization about the wider population.

Adım Adım Çözüm

1
Identify the conclusion of the argument.
Automakers should focus less on fuel efficiency because most car buyers prioritize engine performance.
Finding the main conclusion is the necessary first step to evaluate any logical flaw.
2
Identify the premise supporting the conclusion.
Over 70 percent of surveyed readers of Luxury Auto Weekly prioritize engine performance.
Understanding the evidence allows you to find the gap between the premise and the conclusion.
3
Evaluate the relationship between the premise and the conclusion to spot the logical gap.
The argument jumps from evidence about 'readers of a luxury car magazine' to a conclusion about 'most car buyers'.
This identifies the specific vulnerability in the argument's structure.
4
Characterize the logical flaw based on the identified gap.
The sample group is heavily biased. People who read luxury auto magazines are inherently more likely to care about engine performance than the general population of car buyers.
Pinpointing the exact nature of the flaw leads directly to the correct answer choice.

Anahtar Kavram

Unrepresentative Sample (Selection Bias)
Soru 5Soru →

An argument that generalizes about a population based on a survey is insulated from the flaw of relying on an unrepresentative sample as long as the researchers employed a strictly randomized process to select the individuals who were invited to participate.

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Cevap: False

Cevap

False
The statement is false because it fails to account for non-response bias. A strictly randomized process for selecting invitees does not guarantee that the individuals who actually choose to participate will accurately represent the broader population. If a specific demographic or ideological group is disproportionately likely to return the survey, the resulting sample will be unrepresentative despite the initial randomization.

Adım Adım Çözüm

1
Analyze the condition established in the statement.
The condition states that researchers used a strictly randomized process to select the individuals who were 'invited to participate' in the survey.
Understanding the exact scope of the condition is necessary to evaluate its logical consequences.
2
Identify the logical claim being made about this condition.
The statement claims that this random invitation process 'insulates' the argument from the flaw of relying on an unrepresentative sample.
To determine if the statement is true or false, we must test if the condition absolutely guarantees the claim.
3
Evaluate whether random selection of invitees guarantees a representative final sample.
It does not. While the invitations were random, the actual participation is voluntary. Individuals with strong opinions on the topic are usually more likely to respond, leading to self-selection bias.
A valid survey requires not just random distribution, but a representative pool of actual respondents.
4
Conclude the validity of the statement.
Because an unrepresentative sample can still occur due to non-response bias, the argument is not insulated from this flaw. The statement is therefore false.
Identifying a scenario where the premise is true but the conclusion fails proves the statement is false.

Anahtar Kavram

Sampling and Survey Flaws: Non-Response and Voluntary Response Bias
Soru 6Soru →

A local magazine recently conducted a survey to determine whether the city's residents support the construction of a new public park. The magazine mailed a questionnaire to all of its subscribers and found that 80 percent of the respondents strongly favor the new park. Based on these results, the magazine concluded that a vast majority of the city's residents support the construction of the new park.

Which of the following best describes the flaw in the magazine's reasoning?

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Cevap: It takes for granted that the views of the magazine's subscribers accurately reflect the views of the city's residents as a whole.

Cevap

The argument is flawed because it assumes that the magazine's subscribers are a representative sample of the city's overall population.
The correct answer accurately points out that the argument relies on an unrepresentative sample. The magazine surveyed only its own subscribers, a specific group of people who are not necessarily reflective of the broader city population. Therefore, applying the survey's 80 percent approval rate to the entire city is logically flawed.

Adım Adım Çözüm

1
Identify the conclusion of the argument.
The conclusion is that a vast majority of the city's residents support the new park.
Understanding what the author is trying to prove is the first step in evaluating the reasoning.
2
Identify the premises used to support the conclusion.
The premise is that 80 percent of the magazine's subscribers who responded to a survey favor the park.
Isolating the evidence reveals the foundation of the author's claim.
3
Evaluate the logical connection between the premises and the conclusion to find the flaw.
The argument jumps from a specific subgroup (magazine subscribers) to a general population (city residents) without establishing that the subgroup is representative.
This highlights the sampling bias, which is the core logical vulnerability of the argument.

Anahtar Kavram

Unrepresentative Sample
Tahmini Süre:1m 0s
Soru 7Soru →

Match each flawed argument to the abstract description that best identifies its specific sampling or survey error.

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Öğeler

A manager determines that customer satisfaction is plummeting by surveying only those patrons who asked to speak directly with management.
A television station conducts a phone-in poll and concludes that the vast majority of citizens oppose a new law.
A political campaign concludes that their candidate is widely beloved after asking voters, 'Do you support our honest and hardworking candidate?'
A student interviews two classmates who enjoy classical music and concludes that classical music is highly popular among all students at the university.

Eşleşmeler

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Cevap

The manager's survey matches the predisposed sample flaw; the phone-in poll matches the self-selection flaw; the political campaign matches the biased phrasing flaw; and the student's interviews match the inadequately small sample flaw.
Each scenario perfectly illustrates one distinct category of sampling or survey flaw. By identifying the specific methodological error in the stimulus (e.g., small sample, loaded question, unrepresentative group, voluntary response), we can accurately map it to its formal logical description.

Adım Adım Çözüm

1
Analyze the manager scenario.
Identified that the sample consists only of patrons speaking to management.
This group is overwhelmingly likely to have complaints, matching the description of a sample predisposed to negative views.
2
Analyze the television poll scenario.
Identified that respondents must call in to participate.
This methodology requires voluntary participation, matching the description of a self-selected sample.
3
Analyze the political campaign scenario.
Identified loaded language in the survey question.
Phrases like 'honest and hardworking' push respondents toward a specific answer, matching the biased phrasing flaw.
4
Analyze the student scenario.
Identified that the conclusion about a large university is based on just two people.
Two people cannot represent an entire university, matching the description of an inadequately small number of observations.

Anahtar Kavram

Sampling and Survey Flaws
Soru 8Soru →

A multinational corporation recently introduced a voluntary wellness program for its employees. After one year, an independent consulting firm evaluated the program's effectiveness by surveying employees who had actively participated in the program for at least six months. Over 85 percent of the surveyed employees reported significant improvements in their physical health and a reduction in workplace stress. Based on these results, the consulting firm concluded that the wellness program is highly effective at improving employee well-being and should be implemented across all branches of the corporation.

Which one of the following is the most serious flaw in the consulting firm's argument?

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Cevap: It draws a broad conclusion about the efficacy of a program based on a sample of individuals whose continued participation makes them unrepresentative of the target population.

Cevap

The option stating that it draws a broad conclusion based on a sample of individuals whose continued participation makes them unrepresentative of the target population.
The correct answer accurately identifies that the survey is based on an unrepresentative sample. By only surveying employees who voluntarily participated for at least six months, the consulting firm systematically excluded anyone who might have dropped out early because they found the program ineffective, unhelpful, or overly stressful. Therefore, the sample is heavily skewed toward those who experienced positive results.

Adım Adım Çözüm

1
Analyze the argument's premises.
The premise relies on a survey of employees who voluntarily participated in a wellness program for at least six months, wherein 85 percent of these individuals reported positive results.
Identifying the specific evidence used to support the conclusion is the critical first step in finding the methodological flaw.
2
Identify the argument's conclusion.
The conclusion is that the wellness program is highly effective at improving overall employee well-being and should be implemented universally.
Understanding the broad scope of the conclusion is necessary to see if the limited premises adequately support it.
3
Evaluate the connection between the premises and the conclusion to find the logical gap.
The sample only includes people who stayed in the program for at least six months. It completely excludes anyone who found the program ineffective, overly difficult, or stressful and therefore dropped out early. Thus, the sample is inherently biased toward those who found it beneficial.
This reveals a classic survivorship bias, making the sample unrepresentative of the entire employee population.

Anahtar Kavram

Sampling Flaw (Survivorship and Selection Bias)
Soru 9Soru →

Below are four distinct arguments that rely on statistical, survey, or polling data. Each argument commits a specific methodological fallacy. Pair each argument with the abstract logical description that best characterizes its underlying vulnerability.

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Öğeler

An educational task force evaluated the effectiveness of a demanding three-year academic acceleration program by assessing the standardized test scores of the students enrolled in their third year. Because 98 percent of these students scored in the top percentile, the task force concluded that the program drastically improves the academic performance of any student who enters it.
During a broadcast concerning proposed zoning regulations, a television news anchor directed viewers to participate in an online poll regarding the controversial legislation. Given that 85 percent of the respondents expressed vehement opposition, the network reported that the vast majority of the electorate rejects the zoning changes.
In order to estimate the average amount of sleep adults in a sprawling metropolis get per night, researchers interviewed patrons at several 24-hour coffee shops between the hours of 2:00 AM and 5:00 AM. They subsequently concluded that the typical adult in the metropolis sleeps fewer than five hours per night.
A political campaign distributed a questionnaire that asked, 'Do you support the incumbent's reckless economic policies that threaten to bankrupt our municipality?' Relying on the responses, the campaign manager declared that 90 percent of constituents oppose the incumbent's economic policies.

Eşleşmeler

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Cevap

The educational task force argument matches the survivorship bias description. The television news anchor argument matches the self-selection bias description. The sleep researchers argument matches the anomalous demographic subset description. The political campaign argument matches the loaded inquiry phrasing description.
Each argument commits a distinct sampling or survey flaw. The task force argument is flawed because it measures success only among those who survived a multi-year process (survivorship bias). The news poll is flawed because it relies on viewers motivated enough to respond, who rarely represent the broader population (voluntary response bias). The sleep study is flawed because surveying people at a coffee shop at 3:00 AM guarantees a sample of people with atypical sleep patterns (unrepresentative sample). The political survey is flawed because the loaded wording of the question forces respondents toward a particular answer (framing effect).

Adım Adım Çözüm

1
Analyze the educational task force argument to identify its flaw.
The sample only tests third-year students in a demanding program.
This identifies survivorship bias, matching the description of excluding those who did not complete the process.
2
Analyze the television news anchor argument to identify its flaw.
The poll relies entirely on viewers choosing to call in.
This identifies self-selection or voluntary response bias, matching the description regarding groups whose members self-select.
3
Analyze the sleep researchers argument to identify its flaw.
The survey targets people awake at 3:00 AM at coffee shops.
This identifies an unrepresentative sample, matching the description of a demographic subset whose location and timing make them highly anomalous.
4
Analyze the political campaign argument to identify its flaw.
The survey question uses emotionally charged and loaded language.
This identifies a leading question flaw, matching the description of an inquiry designed to elicit a specific response.

Anahtar Kavram

Identifying Specific Types of Sampling and Survey Flaws in Logical Arguments
Tahmini Süre:3m 0s
Soru 10Soru →

Consider the following argument:

'An independent consumer advocacy group sought to determine the reliability of the newly released Zephyr X-series washing machines. They mailed satisfaction questionnaires to 10,000 people who had purchased a Zephyr X-series machine within the last six months. Of the 1,500 people who returned the questionnaire, nearly 90 percent reported experiencing at least one major mechanical failure. Based on this data, the group concluded that the Zephyr X-series is highly unreliable.'

The primary logical flaw in this argument is that it draws a broad conclusion from a sample size (1,500 respondents) that is statistically too small to represent the experiences of all purchasers.

Cevabı ve açıklamayı göster

Cevap: False

Cevap

False
The statement is false because it misidentifies the methodological flaw. The argument's weakness is not the size of the sample, but its unrepresentative nature. People who experience mechanical failures are disproportionately more motivated to return a satisfaction questionnaire than those whose machines function perfectly. This creates a voluntary response bias. A sample of 1,500 is statistically large enough to form a generalization if the sample is randomly selected and representative, so sample size is not the logical flaw here.

Adım Adım Çözüm

1
Analyze the argument's premise and conclusion.
Premise: 90% of the 1,500 returned surveys reported a major failure. Conclusion: The washing machines are highly unreliable.
Identifying the core argument structure is necessary to evaluate its logical validity.
2
Examine the data collection methodology.
Questionnaires were mailed to 10,000 people, and 1,500 independently chose to return them.
Understanding how the sample was gathered reveals potential methodological biases.
3
Evaluate the statement's claim about the logical flaw.
The statement claims the primary flaw is a sample size that is statistically too small.
To determine if the provided statement correctly identifies the methodological error in the text.
4
Compare the claim against logical principles of sampling.
A sample size of 1,500 is mathematically large enough for statistical significance. The actual flaw is self-selection bias, as angry customers are highly motivated to respond.
To reach the final evaluation that the statement misidentifies the true sampling flaw.

Anahtar Kavram

Distinguishing between inadequate sample size and unrepresentative sample bias (voluntary response bias).
Soru 11Soru →

A manufacturer of various athletic equipment recently released a premium line of smart treadmills. To assess overall customer satisfaction with the manufacturer's entire range of products, the company emailed a survey exclusively to customers who had registered the new smart treadmills for warranty purposes. Over 95 percent of the respondents reported being extremely satisfied with their purchase. Based on this, the company's executive team concluded that nearly all of their customers are highly satisfied with the brand.

The reasoning in the executive team's argument is most vulnerable to criticism on the grounds that it

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Cevap: draws a broad conclusion about the manufacturer's entire customer base from a sample that is unlikely to be representative of that group

Cevap

The argument draws a broad conclusion about the manufacturer's entire customer base from a sample that is unlikely to be representative of that group.
The correct answer accurately points out that the survey respondents (buyers of a specific premium treadmill who registered for a warranty) do not accurately represent the target population of the conclusion (all customers of the manufacturer's various athletic equipment). People buying premium products might have a different experience than those buying standard products, and those who bother to register for warranties might be more invested in the brand than the average consumer.

Adım Adım Çözüm

1
Identify the conclusion of the argument.
The conclusion is that 'nearly all of their customers are highly satisfied with the brand.'
This is the final claim that the author is trying to prove using the survey data.
2
Identify the premises (evidence) provided to support the conclusion.
The evidence is that over 95% of customers who bought the new premium smart treadmills and registered them for warranty reported being extremely satisfied.
Understanding the evidence is necessary to see if it adequately supports the conclusion.
3
Evaluate the relationship between the premises and the conclusion to find the logical gap.
The conclusion is about ALL customers who buy ANY athletic equipment from the manufacturer. The evidence is only about a specific subgroup: those who bought premium treadmills AND registered for a warranty.
Finding the mismatch in scope between the evidence and the conclusion reveals the flaw.
4
Determine the type of flaw occurring.
Because the subgroup surveyed is not representative of the broader population in the conclusion, this is a Sampling and Survey Flaw.
Matching the logical gap to a known LSAT flaw category makes it easier to find the correct answer choice.

Anahtar Kavram

Sampling Flaw - Unrepresentative Sample
Tahmini Süre:1m 30s
Soru 12Soru →

Linguist: To determine whether early exposure to multiple languages enhances cognitive flexibility, researchers tracked two groups of children over ten years: one group raised in bilingual households and another raised in monolingual households. To ensure the study measured sustained language exposure, the researchers excluded any child who failed to maintain fluency in all the languages spoken in their respective households throughout the decade. At the end of the study, the bilingual cohort scored significantly higher on cognitive flexibility assessments. Therefore, early exposure to multiple languages enhances cognitive flexibility.

The linguist's reasoning is most vulnerable to criticism on the grounds that it

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Cevap: incorporates a selection criterion for its sample that is likely to favor individuals who possess the very cognitive trait the researchers were investigating

Cevap

The correct answer is the option stating that the argument incorporates a selection criterion for its sample that is likely to favor individuals who possess the very cognitive trait the researchers were investigating.
The correct answer accurately identifies the critical sampling flaw in the study's methodology. By establishing a rule that excludes any child who failed to maintain language fluency over a ten-year period, the researchers likely eliminated subjects who inherently possessed lower cognitive flexibility. Because this exclusion disproportionately filters the bilingual group (who had the much harder task of maintaining multiple languages), the final sample is fundamentally skewed. The surviving bilingual cohort consists primarily of children who already had the cognitive tools necessary to maintain multiple languages, rendering the final comparison invalid.

Adım Adım Çözüm

1
Identify the conclusion of the argument.
The conclusion is: 'Therefore, early exposure to multiple languages enhances cognitive flexibility.'
Understanding the exact claim being made is necessary to evaluate the evidence provided.
2
Analyze the premises and the methodology used to reach the conclusion.
Researchers tracked two groups over ten years but applied a strict exclusion criterion: they removed any child who failed to maintain fluency in all household languages.
In Logical Reasoning questions involving studies, the methodology often contains the core logical vulnerability.
3
Evaluate the relationship between the methodology and the conclusion to find the logical gap.
Maintaining fluency in multiple languages over a decade is cognitively demanding. Children with lower cognitive flexibility are more likely to drop a language and be excluded. Thus, the final bilingual sample consists primarily of those who inherently possessed high cognitive flexibility to begin with.
This reveals a severe selection bias (survivorship bias). The sample is skewed by the very trait it aims to measure.
4
Match the discovered flaw with the answer choices.
The correct option abstractly describes this methodological flaw by noting the selection criterion favors those who already possess the investigated trait.
The correct answer must accurately and precisely describe the structural weakness in the argument's reasoning.

Anahtar Kavram

Selection Bias / Unrepresentative Sample
Soru 13Soru →

An argument states: 'A public health organization sought to determine the average weekly exercise habits of adults in the nation. The organization mailed a comprehensive questionnaire to 50,000 randomly selected households. Of the 4,200 adults who completed and returned the questionnaire, 78% reported exercising for at least 150 minutes per week. Based on these results, the organization concluded that a strong majority of adults in the nation meet the standard recommendation of 150 minutes of weekly exercise.'

Statement: The organization's argument is flawed primarily because a sample of 4,200 respondents is inherently too small to provide a statistically reliable estimate for an entire national adult population.

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Cevap: False

Cevap

The statement is False. The argument's flaw is an unrepresentative sample caused by non-response bias, not an inherently insufficient sample size.
The statement is false because it misidentifies the logical flaw. A sample size of 4,200 is highly robust for a national estimate if the sample is truly random and unbiased. The argument actually suffers from a representativeness flaw (specifically, non-response bias), because the subset of people who take the time to fill out and return a health questionnaire are likely to have vastly different exercise habits than the 45,800 who threw it away.

Adım Adım Çözüm

1
Analyze the methodology used in the argument to gather data.
The organization sent 50,000 surveys, but only 4,200 were returned. The conclusion about the national population is based entirely on the habits of those 4,200 respondents.
Understanding how the sample was generated is necessary to identify any methodological flaws.
2
Evaluate the specific criticism made in the provided statement.
The statement claims the argument is flawed specifically because the sample size of 4,200 is 'inherently too small' to represent the national population.
To determine if the statement is true or false, we must assess whether a 'small sample size' is the actual logical violation occurring in the stimulus.
3
Assess the statistical validity of the sample size versus its representativeness.
A sample of 4,200 is mathematically large enough to yield a statistically significant estimate for a national population, provided the sample is unbiased. However, the low response rate introduces severe non-response bias, meaning the 4,200 respondents are unlikely to be representative of the whole.
Distinguishing between sample size (quantity) and sample bias (quality) is critical for accurately diagnosing the flaw.
4
Determine the truth value of the statement.
Because the actual flaw is non-response bias (unrepresentative sample) rather than a small sample size, the statement incorrectly diagnoses the logical error.
An incorrect diagnosis of an argument's flaw makes the evaluative statement false.

Anahtar Kavram

Distinguishing between an insufficient sample size and an unrepresentative sample (non-response/voluntary response bias).
Tahmini Süre:1m 30s
Soru 14Soru →

City councilor: We recently distributed a survey to individuals holding annual vehicle registration passes in the metropolitan area to measure support for expanding the car-free downtown plazas. Of the thousands who mailed back their responses, an overwhelming majority indicated they fiercely oppose expanding the plazas. Consequently, we can safely conclude that the wider public does not want the car-free plazas to be expanded.

Which one of the following most accurately describes a flaw in the city councilor's reasoning?

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Cevap: It bases a generalization about a population on a sample that is systematically predisposed to hold a particular view on the issue in question.

Cevap

The correct answer identifies that the argument bases a generalization about a population on a sample that is systematically predisposed to hold a particular view on the issue in question.
The city councilor concludes that the 'wider public' opposes the plazas based entirely on a survey sent only to individuals with vehicle registration passes. People who own and drive vehicles are uniquely disadvantaged by car-free plazas because they lose driving space and parking access. Therefore, their views are highly unlikely to be representative of the general population, which includes pedestrians, cyclists, and public transit users. The argument is fundamentally flawed because it relies on an unrepresentative, systematically biased sample.

Adım Adım Çözüm

1
Identify the conclusion and the premise of the argument.
Conclusion: The wider public does not want the car-free plazas expanded. Premise: An overwhelming majority of surveyed vehicle registration pass holders oppose the expansion.
Breaking the argument down into its structural components makes it easier to evaluate the relationship between the provided evidence and the final claim.
2
Evaluate the relationship between the sample group and the target population.
The sample consists exclusively of vehicle registration pass holders (car owners), while the conclusion makes a sweeping claim about the 'wider public'.
In any survey-based argument, the sample must be sufficiently representative of the target population for the conclusion to logically follow.
3
Identify any inherent bias in the sample regarding the specific issue.
Car owners are directly negatively impacted by car-free plazas due to a loss of driving and parking access. Thus, they are structurally more likely to oppose the policy than non-drivers.
If the sample group has a vested interest or systematic bias that differs from the general population, the survey results cannot be reliably projected onto everyone else.

Anahtar Kavram

Sampling Bias (Unrepresentative Sample)
Soru 15Soru →

City Planner: Critics argue that converting downtown commercial streets into pedestrian-only zones harms local retail economies by restricting vehicular access. However, a comprehensive review of pedestrian-only zones established nationwide over the last two decades demonstrates otherwise. Researchers analyzed the financial trajectories of the retail businesses currently operating within these zones. After controlling for regional economic trends and inflation, the data shows that these businesses experienced, on average, a 30 percent increase in both their profit margins and absolute net profits following the transition. Clearly, pedestrianizing commercial streets profoundly enhances retail profitability.

Which one of the following most accurately describes a flaw in the city planner's reasoning?

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Cevap: It bases a generalization about the economic impact of a policy on a sample that systematically omits entities that failed to survive that policy.

Cevap

The argument bases a generalization about the economic impact of a policy on a sample that systematically omits entities that failed to survive that policy.
The correct answer accurately identifies a severe sampling flaw known as survivorship bias. By restricting the economic review exclusively to businesses 'currently operating' in the pedestrian zones, the researchers systematically excluded any businesses that suffered financial ruin and closed due to the policy change. Thus, the sample is inherently biased and cannot logically support a general conclusion about the policy's overall impact on retail profitability.

Adım Adım Çözüm

1
Analyze the city planner's conclusion.
The conclusion is that pedestrianizing commercial streets profoundly enhances retail profitability.
Identifying the main conclusion is the required first step in evaluating any logical argument's structure.
2
Examine the premises supporting the conclusion.
The evidence relies on a review of retail businesses 'currently operating' within pedestrian-only zones, which show a 30 percent increase in profit margins and absolute net profits after controlling for regional trends.
Understanding the precise evidence and the parameters of the study reveals the structural limits of the argument.
3
Identify vulnerabilities or gaps between the premises and the conclusion.
The study exclusively evaluated businesses that are 'currently operating.' It excluded any businesses that went bankrupt, closed, or relocated immediately following the pedestrianization. This introduces a severe survivorship bias.
In sampling flawed arguments, the data subset usually excludes a critical demographic that would actively undermine the conclusion.
4
Select the option that accurately describes this specific sampling flaw.
The correct option identifies that the generalization is based on a sample omitting entities that failed to survive the policy change.
This abstract phrasing precisely matches the identified survivorship bias within the stimulus.

Anahtar Kavram

Sampling and Survey Flaws (Survivorship Bias)
Tahmini Süre:2m 0s
Soru 16Soru →

University administrator: To determine how our alumni feel about the recent shift toward online-only summer courses, we analyzed responses from our annual donor satisfaction survey, which was mailed exclusively to alumni who contributed $500 or more to the university last year. Over 80 percent of respondents indicated they strongly support the shift. Therefore, it is clear that the overwhelming majority of our alumni favor the transition to online-only summer courses.

Which one of the following most accurately describes a flaw in the university administrator's reasoning?

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Cevap: generalizes about the attitudes of an entire group based on the opinions of a subset that is likely unrepresentative

Cevap

The correct answer is the option stating that the argument generalizes about an entire group based on an unrepresentative subset.
The correct answer accurately diagnoses the sampling bias in the argument. The administrator is trying to draw a conclusion about the entire alumni population, but uses evidence derived exclusively from a highly specific, non-random subset: alumni who donated at least $500. This group is likely to be systematically different from the broader alumni base (e.g., they may be wealthier, older, or more supportive of the administration's decisions in general), making the sample fundamentally unrepresentative.

Adım Adım Çözüm

1
Identify the conclusion of the argument.
The conclusion is: 'it is clear that the overwhelming majority of our alumni favor the transition to online-only summer courses.'
Finding the conclusion clarifies exactly what the author is trying to prove.
2
Identify the premise (evidence) supporting the conclusion.
The premise is that over 80 percent of respondents to a survey sent to alumni who contributed $500 or more support the shift.
Understanding the evidence is necessary to see the gap between the premise and the conclusion.
3
Evaluate the relationship between the premise and the conclusion to find the logical gap.
The evidence relies entirely on alumni who made significant financial donations, but the conclusion makes a claim about all alumni. Financial donors are a self-selected, highly engaged subset whose opinions likely differ from the general alumni population.
Recognizing this gap isolates the specific vulnerability (flaw) in the reasoning.
4
Match the identified flaw with the correct abstract description in the choices.
The flaw is an unrepresentative sample, which perfectly matches the option describing a generalization based on a likely unrepresentative subset.
LSAT Flaw questions require mapping your specific critique of the argument to the generalized, abstract language used in the correct answer choice.

Anahtar Kavram

Unrepresentative Sample / Survey Bias
Tahmini Süre:1m 30s
Soru 17Soru →

Consider the following argument:

An independent researcher wanted to determine the average daily screen time of teenagers. The researcher recruited 500 teenagers who were attending an annual weekend video gaming convention and tracked their screen time for a month. The results showed an average of 8 hours of screen time per day. The researcher concluded that teenagers, on average, spend 8 hours per day looking at screens.

Evaluate the following statement about the argument as true or false:

The primary logical flaw in the researcher's argument is that the sample size of 500 is too small to draw a reliable statistical conclusion about the general population of teenagers.

Cevabı ve açıklamayı göster

Cevap: False

Cevap

False
The statement is false because it misidentifies the logical flaw. The argument's vulnerability lies in its reliance on an unrepresentative sample (selection bias). Teenagers attending a video gaming convention are practically guaranteed to have higher-than-average screen times compared to the general population. Even if the sample size were 50,000, the conclusion would still be flawed. Therefore, the issue is not the sample size (500 is typically mathematically sufficient), but rather the biased nature of the sample source.

Adım Adım Çözüm

1
Analyze the scope of the argument's conclusion relative to its premises.
The conclusion generalizes about all teenagers based on data collected from a sample of 500 teenagers attending a gaming convention.
Identifying the gap between the evidence provided and the broad conclusion drawn reveals potential logical flaws.
2
Identify the primary vulnerability in the argument's sampling methodology.
The sample group (gaming convention attendees) is highly likely to have significantly more screen time than the average teenager, making the sample fundamentally unrepresentative.
A representative sample is required to draw valid generalizations about a larger target population.
3
Evaluate the provided statement against the identified flaw.
The statement inaccurately claims the flaw is a small sample size. In reality, 500 is generally a sufficient sample size if randomized; the actual fatal flaw is selection bias.
Distinguishing between sample size (quantity) and sample representativeness (quality) is necessary to accurately determine the statement's truth value.

Anahtar Kavram

Distinguishing between sample size and sample representativeness
Soru 18Soru →

Match each flawed argument scenario on the left with the abstract description of its specific sampling or survey flaw on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

A news anchor concludes that the city overwhelmingly opposes a new tax based on emails sent by viewers during a broadcast.
An author asserts that a specific business strategy ensures long-term wealth by analyzing the habits of fifty currently successful billionaires.
A researcher determines that a national candidate is unpopular with youth after surveying students at a single, politically homogeneous private college.
A consumer claims a new vehicle model has defective brakes because three recent buyers reported brake failures within a week of purchase.

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The viewer emails scenario maps to individuals who actively opted to express opinions. The billionaire scenario maps to entities that have already survived a selection process. The private college scenario maps to a remarkably narrow and unrepresentative demographic subset. The brake failure scenario maps to an inadequately small number of isolated anecdotes.
Each flawed argument neatly maps to a distinct sampling error. The email survey fails due to self-selection (voluntary response bias). The billionaire study is flawed because it ignores those who failed (survivorship bias). The college poll surveys an insular group to make a broad claim (unrepresentative demographic subset). The brake failure claim relies on too few data points (small sample size).

Adım Adım Çözüm

1
Analyze the news anchor scenario.
Identified that the sample relies entirely on people who actively chose to send emails.
This matches the abstract description of voluntary opt-in response bias.
2
Analyze the billionaire scenario.
Identified that the sample only includes people who are already financially successful.
This matches the abstract description of survivorship bias, which ignores failures.
3
Analyze the college student scenario.
Identified that the sample represents a very specific, homogeneous group rather than the diverse national youth population.
This matches the abstract description of surveying a narrow, unrepresentative demographic subset.
4
Analyze the vehicle buyer scenario.
Identified that the sweeping conclusion is based on merely three incidents.
This matches the abstract description of generalizing from an inadequately small number of anecdotes.

Anahtar Kavram

Identifying the specific mechanism by which a sample fails to accurately represent the target population in inductive reasoning.
Tahmini Süre:1m 30s
Soru 19Soru →

University Administrator: To assess whether the 'Skills-First' curriculum implemented three years ago has adequately prepared our students for the workforce, we evaluated feedback from recent alumni. Questionnaires were sent to all graduates from the past three years who currently maintain active memberships in the university's philanthropy network. Over 80 percent of the respondents indicated that they are excelling in their careers and credited the curriculum for their achievements. This clearly demonstrates that the new curriculum successfully prepares our students for professional success.

The reasoning in the university administrator's argument is flawed in that the argument

Cevabı ve açıklamayı göster

Cevap: projects survey results from a specific subgroup of alumni onto the broader graduate population, even though membership in that subgroup is strongly associated with the outcome being measured

Cevap

The argument projects survey results from a specific subgroup of alumni onto the broader graduate population, even though membership in that subgroup is strongly associated with the outcome being measured.
The argument attempts to establish the overall effectiveness of a curriculum based on a survey. However, the survey was exclusively sent to members of the university's philanthropy network. Alumni who donate money to their university are disproportionately likely to be financially secure and successful in their careers. Therefore, this sample is unrepresentative of the entire graduating class, and their highly positive feedback cannot be reliably projected onto all recent alumni. The correct answer accurately identifies this severe sampling bias.

Adım Adım Çözüm

1
Identify the main conclusion of the argument.
The new 'Skills-First' curriculum successfully prepares students for professional success.
Understanding the exact scope of the conclusion is necessary to determine if the evidence provided is sufficient to support it.
2
Identify the premises supporting this conclusion.
A survey of graduates from the past three years who are active in the university's philanthropy network showed that over 80 percent are excelling in their careers and credit the curriculum.
We must isolate the evidence the author uses to justify their generalized claim.
3
Evaluate the relationship between the premises and the conclusion to find the logical gap.
The conclusion makes a broad claim about all students, but the premise relies on a very specific, self-selected sample: members of a philanthropy network. Alumni who donate money are inherently more likely to be financially secure and successful.
This reveals a classic unrepresentative sample flaw: the surveyed group is biased toward the very characteristic (success) being measured.
4
Select the option that accurately describes this sampling flaw in abstract terms.
The correct option notes that the argument projects findings from a subgroup onto a broader population, despite membership in that subgroup being tied to the measured outcome.
This perfectly matches the identified flaw without falling for irrelevant traps regarding causation or absolute numbers.

Anahtar Kavram

Unrepresentative Sample Bias (Sampling Flaw)
Soru 20Soru →

An argument that draws a general conclusion about the effectiveness of a new teaching method by studying only schools that volunteered to implement the method avoids sampling bias as long as the sample size is sufficiently large.

Cevabı ve açıklamayı göster

Cevap: False

Cevap

False
The statement is false because self-selection bias cannot be cured merely by increasing the sample size. If a sample is fundamentally unrepresentative due to how it was gathered, gathering more data using the exact same flawed method will only result in a larger, but equally biased, sample.

Adım Adım Çözüm

1
Analyze the sampling methodology described in the argument's premise.
The sample consists exclusively of schools that 'volunteered' to implement the new method.
Identifying exactly how a sample is selected is the critical first step in evaluating its representativeness.
2
Evaluate the relationship between volunteer status and potential bias.
Voluntary samples often exhibit systematic differences from the general population, a flaw known as self-selection bias.
Volunteers may be more motivated, better funded, or more open to change than the average school, skewing any results.
3
Determine the impact of sample size on this specific selection bias.
A sufficiently large sample size does not eliminate or mitigate the bias introduced by a flawed, non-random selection process.
A large unrepresentative sample simply provides a more precise estimate of an inherently biased result.

Anahtar Kavram

Sample Size vs. Sample Representativeness
Tahmini Süre:45s
Sampling and Survey Flaws Alıştırma Soruları — LSAT | Examkin