Question 74·Medium·Inferences
A school district offered free weekend study workshops for its algebra courses. After the first semester, students who attended the workshops showed greater average score gains than students who did not. The district promoted this as evidence that the workshops caused the improvement. However, attendance was voluntary, and a district survey found that students who signed up were more likely to say they "enjoy studying" and "often work ahead." Therefore, a reasonable inference is that ______
Which choice most logically completes the text?
For "Which choice most logically completes the text?" questions, first identify the author’s main claim, then pay close attention to any contrast words (like "however," "but," or "although") that signal a shift or complication. Ask what the new information does to the original claim—does it weaken it, explain it, or add an exception? Then choose the option that directly connects that new information to a reasonable, not extreme, conclusion, and eliminate answers that introduce new ideas, exaggerate beyond the text, or contradict what is stated.
Hints
Locate the contrast in the passage
Notice the word "However": it introduces information that challenges the district’s claim. Focus on how the voluntary attendance and survey results might weaken the idea that the workshops alone caused the gains.
Think about who chose to attend
Ask yourself: if the students who went to the workshops already enjoy studying and work ahead, how might that affect their scores even without the workshops?
Match the tone and strength of the conclusion
The question asks for a "reasonable inference," not a strong or absolute claim. Eliminate choices that make extreme statements or introduce new ideas (like fully predicting the results of a new policy) that the passage never mentions.
Check for new, unsupported claims
Look out for answers that talk about bias in test scores, zero improvement, or guaranteed future outcomes. Does the passage actually give evidence for any of those, or are they going beyond the information given?
Step-by-step Explanation
Understand the main claim and the new information
First, restate the situation in your own words:
- The district observes that workshop attendees improved more than non-attendees.
- The district claims this proves the workshops caused the improvement.
- But attendance was voluntary, and the survey shows attendees are more likely to enjoy studying and work ahead.
So there is a possible difference between the two groups besides just the workshops: their motivation and study habits.
Recognize the issue: correlation vs. causation
The district is treating a correlation (attending workshops goes with higher gains) as if it proves causation (workshops directly caused the gains).
The extra survey information suggests a confounding factor: students who chose to attend already had stronger study habits. That means something else, besides the workshops, could explain the score gains.
Figure out what a ‘reasonable inference’ should do
A reasonable inference should:
- Be based directly on information the passage gives.
- Offer a cautious, plausible explanation.
- Not introduce new claims (like “mandatory” rules or “biased test scores”) that aren’t supported.
So the completion should connect:
- Voluntary attendance
- Higher motivation/study habits of attendees
- The interpretation of the score gains.
Evaluate each answer choice against the passage
Now compare the choices:
- Choice B talks about biased survey questions and then jumps to saying test scores cannot be trusted—this mixes up survey bias and test score reliability, which the passage never suggests.
- Choice C says non-attendees did not improve at all, but the passage only says they improved less, not that they had zero gain.
- Choice D claims making workshops mandatory would eliminate all score differences. The passage never discusses what would happen if attendance changed, so this is a big, unsupported prediction.
- Choice A directly uses the idea that more motivated students chose to attend, suggesting their higher gains may partly come from that, not just the workshops. This fits the warning about drawing causal conclusions from voluntary participation.
Therefore, the best completion is: A) the higher gains among attendees may be due in part to self-selection by more motivated students rather than the workshops themselves.