Question 48·Hard·Command of Evidence
Researchers investigating whether text-message reminders boost attendance at community financial-literacy workshops predicted that participants who receive reminders will be substantially more likely to attend than those who do not.
After 600 people registered for an upcoming workshop, the researchers randomly assigned half to receive a reminder text the day before the event and half to receive no reminder. The outcomes are summarized below.
| Outcome | Reminder sent | No reminder |
|---|---|---|
| Registered participants | 300 | 300 |
| Attended workshop | 180 | 175 |
Which choice best describes information from the table that weakens the researchers’ prediction?
For table-based command-of-evidence questions, identify what comparison the claim is making (here, likelihood of attending). Translate the table into comparable rates (attended ÷ registered) for each group, then compare those rates in percentage points. Choose the option that accurately captures the size of that difference and its implication for the claim’s wording (such as “substantially”).
Hints
Clarify what needs to be weakened
To weaken the prediction, look for evidence that reminders did not make attendance substantially more likely.
Convert to attendance rates
Compute the attendance rate for each group: attended ÷ registered.
Compare in percentage points
Subtract the no-reminder attendance rate from the reminder attendance rate. Is the gap large enough to be called “substantial”?
Step-by-step Explanation
Restate what would weaken the prediction
The prediction claims reminders make attendance substantially more likely, so evidence that the two groups’ attendance rates are very similar would weaken it.
Compute each group’s attendance rate
- Reminder group: .
- No-reminder group: .
Find the difference in percentage points
The difference in attendance rates is about:
That is about percentage points, which is a small change—not “substantial.”
Select the choice that matches that small difference
The statement that best weakens the prediction is:
The reminder group’s attendance rate was under 2 percentage points higher than the no-reminder group’s rate.