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Find an alternative cause

Identify evidence that weakens a causal conclusion without disputing the reported observation.

Question

A library extended its opening hours in May, and its monthly visits rose by 20%. The director concludes that the longer hours caused the increase. Which additional fact most weakens that conclusion?

  1. a.A nearby library closed for repairs throughout May.
  2. b.The library’s total monthly budget did not change.
  3. c.Several visitors said they appreciated the later closing time.
  4. d.The library has measured visits using the same counter for years.
  5. e.The director plans to keep the new hours in June.

Correct answer

A. A nearby library closed for repairs throughout May.

Full reasoning

  1. 1Separate the premise, a 20% rise after the schedule change, from the conclusion that the schedule change caused it.
  2. 2Look for another change that could account for the same observation.
  3. 3A nearby closure can redirect visitors, so it weakens the attribution to longer hours alone. It does not prove that longer hours had no effect.
  4. 4The other choices concern cost, approval, measurement consistency or a later decision. None provides an equally direct alternative explanation for the rise.

Why each choice is right or wrong

Choice A

Correct. Its visitors may have moved to this library, providing another explanation for the increase without denying that visits rose.

Choice B

An unchanged budget does not determine why visits increased; it does not isolate opening hours from other causes.

Choice C

This supports a possible benefit of the longer hours, so it does not directly challenge the proposed explanation.

Choice D

Consistent measurement makes the before-and-after comparison more credible, but does not identify its cause.

Choice E

A future policy decision provides no evidence about which change caused the observed increase in May.

Related formula

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Sources

Original authored exercise; no database question ID and no protected or official exam-bank content. Specialist review pending.

  1. Introduction to Philosophy, Section 5.3: Arguments — OpenStax. Accessed 2026-08-03. OpenStax textbook content is CC BY-NC-SA 4.0; attribute and avoid verbatim reuse beyond short cited references.
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Sources last checked 2026-09-13

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