A study inference question tests what you can conclude from a comparison between groups. Read the lead-in to see what the blank needs, then name each group, what it received, and what changed. Ask what the groups shared, because a cause shared by both groups can’t explain their difference. If the groups differ in several ways, you can’t tell which one mattered most, so predict the smallest supported conclusion. Wrong choices often add causes the study never tested.
Hints
- Hint 1
Start with the sentences describing the displays and the leaflets. Name what each group received.
- Hint 2
Look for each group’s change in recycling rates, then check the final sentence about outreach. What did the researchers change, and what did they leave out?
- Hint 3
Use both groups’ results to predict the smallest conclusion the comparison supports. Does the study separate the different features of the messages, or test them together?
Step-by-step
Compare the groups and limit the claim
Step 1Name what each group received
The displays showed residents, in real time, how much waste their street had kept out of landfills. What did the comparison neighborhoods get? They received only a monthly leaflet reminding them of pickup schedules. Since the blank asks what the findings suggest, we’re looking for what this difference in messages can reasonably explain.
- Step 2
Compare the changes in recycling
How did recycling change in each group? Rates in the display neighborhoods increased by 24 percent, while rates in the leaflet neighborhoods did not change. That supports a benefit from the displays in this study. Our prediction should be about how much residents recycled, because that’s what the researchers measured.
- Step 3
Check what the comparison can explain
What could explain that difference? The text describes comparable neighborhoods and says the researchers conducted no additional outreach during the study period, so extra outreach by the researchers is already ruled out. But the messages differed in when they arrived, how residents saw them, and whether they reported progress or pickup schedules. The displays seem to have helped, but we can’t tell which feature mattered most.
- Step 4
Match the claim to the evidence
Which wording stays within what the findings most strongly suggest? The phrase immediate, visible information about recycling progress describes the displays, and than periodic reminders alone keeps the comparison tied to the leaflet group. The word can makes this a possible benefit, not a guarantee. Choice C.