Examkin

Question

Difficulty: Very hardIdentifying Logical Flaws and Reasoning Vulnerabilities

Over the past three years, the transit authority of a major metropolitan area instituted a policy requiring daily mechanical inspections of its bus fleet, whereas previously inspections occurred on a weekly basis. During this same three-year period, the average number of unscheduled service interruptions per bus decreased by 40 percent. The head of the transit authority concluded that conducting daily mechanical inspections was the primary cause of the reduction in unscheduled service interruptions and recommended that all municipal transit agencies adopt daily inspection schedules. Which of the following highlights the primary vulnerability in the reasoning of the head of the transit authority?

  1. It fails to consider that another concurrent development, such as the gradual replacement of older buses with newer models, could account for the decrease in unscheduled service interruptions.Answer
  2. B
    It mistakes an effect for a cause by assuming that the reduction in unscheduled service interruptions led transit officials to institute daily mechanical inspections.
  3. C
    It presumes without entitlement that passenger satisfaction ratings are exclusively determined by the frequency of unscheduled service interruptions.
  4. D
    It rejects the possibility that weekly mechanical inspections could ever be executed without incurring prohibitive operational expenditure.
  5. E
    It treats a condition that is necessary for reducing unscheduled service interruptions as though it were sufficient to ensure that no breakdowns ever occur.

Answer

The argument fails to consider that another concurrent development, such as the gradual replacement of older buses with newer models, could account for the decrease in unscheduled service interruptions.
The correct answer identifies the fundamental flaw in the argument's causal reasoning. The author observes that a policy change (daily inspections) coincided over a three-year window with a 40 percent reduction in unscheduled interruptions and concludes that the policy change caused the reduction. However, over a extended period of three years, other relevant factors—such as replacing old, failure-prone buses with new ones—could easily account for the improvement. By failing to control for or rule out such confounding variables, the author's causal conclusion remains unsubstantiated.

Step-by-Step Solution

1
Deconstruct the argument structure into premises and conclusion
Premise: Daily inspections replaced weekly inspections over three years. Premise: Unscheduled service interruptions fell by 40% during those three years. Conclusion: Daily inspections were the primary cause of the reduction.
Identifying the author's precise premise-to-conclusion link is necessary to isolate the logical leap.
2
Evaluate the causal jump in the author's reasoning
The argument observes a correlation over a three-year period between a policy change (daily inspections) and an outcome (fewer interruptions) and claims a direct cause-and-effect relationship.
Correlation between two events occurring in the same time frame does not automatically establish direct causation.
3
Identify potential logical vulnerabilities and alternative explanations
Over a multi-year period, confounding variables—such as fleet modernization, route changes, or driver retraining—could have caused the drop in breakdowns independent of inspection frequency.
A valid causal argument must rule out obvious confounding factors that could produce the observed effect.

Key Concept

Causal Fallacy / Confounding Variables
Rate this question

Topics

Identifying Logical Flaws and Reasoning Vulnerabilities

More questions from this topic