A non-profit organization promoting literacy argues that providing free books to low-income families will significantly improve children's reading comprehension. They cite studies showing a correlation between home library size and children's reading levels. Which of the following, if true, most seriously undermines the organization's argument by suggesting an alternative explanation for the correlation?
- AParents in families with larger home libraries are often more educated themselves and actively engage in reading with their children.
- BChildren's reading comprehension is also influenced by school quality and teacher effectiveness.
- CThe type of books provided free might not always align with children's interests, leading to low engagement.
- DMany low-income families have limited space, making it difficult to store a large number of books.
Show answer & explanationAnswer & explanation
Correct answer: A. Parents in families with larger home libraries are often more educated themselves and actively engage in reading with their children.
The organization's argument makes a causal leap from correlation (home library size and reading levels) to causation (free books improve comprehension). Option B introduces a confounding variable: parental education and engagement. These factors could lead to both larger home libraries AND better reading comprehension, thus providing an alternative explanation for the observed correlation and undermining the direct causal claim of simply providing free books.
Why the other options are wrong
- B. While true, this is a general statement about reading comprehension and doesn't offer a specific alternative explanation for the *correlation between home libraries and reading levels* as strongly as option B does.
- C. This suggests a potential limitation or inefficiency of the program but doesn't provide an alternative explanation for the *existing correlation* between home library size and reading levels.
- D. This points to a practical challenge for the program but doesn't undermine the *causal link* between books and comprehension, only the feasibility of having many books.
Undermining Causal Claims (Confounding Variable)
To undermine a causal claim by suggesting an alternative explanation means to identify a third factor that could be responsible for both the presumed cause and the presumed effect, thereby showing the original causal link might be spurious.
- Specifically targets 'X causes Y' conclusions.
- Introduces a 'Z' that causes both 'X' and 'Y'.
- Does not directly refute the correlation, but its causal interpretation.
Memory trick: Two dancers linked by a hidden string, not by their own will.