An inference question about a study tests what a comparison between groups can show. Start with the claim about what caused the change, then name each group and its result. Ask how people entered the groups and what else the text says about them. If the groups differ in another way that could affect the result, the study can't separate the possible causes. Keep your conclusion within what the study tested, because a difference in results doesn't settle every question about why it happened.
Hints
- Hint 1
Look at how students entered the two groups, then read what the survey says about those who signed up.
- Hint 2
Ask whether the study can separate the possible causes of the higher gains. Use both the attendance rule and the survey to answer.
Step-by-step
Test the district's cause claim
Step 1Compare the score gains
Students who attended showed greater average score gains than students who didn't attend. Does that show that the workshops caused the improvement? That's the district's claim, but a score gap shows who improved more, not yet why. The blank asks for a conclusion the whole study supports.
- Step 2
Find the second difference
How did students end up in each group? Because attendance was voluntary, students chose whether to attend rather than being assigned by chance. The survey adds that those who signed up were more likely to say they "enjoy studying" and "often work ahead." These habits suggest a motivation gap, which could also affect score gains.
- Step 3
Limit the cause claim
More motivated students might improve through their own study, so the survey gives another possible cause of the score gap. Can we conclude that the workshops caused the improvement? The comparison can't separate the two causes, because attendees went to workshops and also reported different study habits. We can question the district's claim without deciding that the workshops had no benefit.
- Step 4
Test the wording
Which wording keeps this at the level of a reasonable inference? Self-selection means people choose to join a group, so it names how more motivated students could end up attending. The phrase may be due in part leaves room for more than one cause: motivation could explain some of the gap without ruling out a workshop benefit. Choice A.