Passage Summary: A study found that the kids who spent the most time hitting the books got worse grades than those who didn't, yet the researchers still insist that studying is the key to success.

Reasoning: Researchers maintained that studying improves grades despite data showing that the students who studied the most actually received lower grades than those who studied less.

Analysis: This scenario presents a classic correlation-versus-causation problem. To explain why the researchers still believe their hypothesis, we need a factor that accounts for why the high-study group was struggling. Perhaps the students who studied the most were those who found the material most difficult and would have failed entirely without that extra effort. Look for an answer that addresses the baseline academic ability of the students involved.