Question 117·Hard·Command of Evidence
In their 2021 longitudinal study of four Midwestern cities, urban ecologists Fernando Ruiz and Janelle Cho examined the practice of converting vacant lots into community-managed pollinator gardens. They found that within two years of installation, the gardens significantly increased local bee and butterfly populations. Citing research on ecosystem connectivity, Ruiz and Cho predict that if the practice expands citywide, pollinator numbers in adjacent suburban and rural areas will rise as well.
Which finding, if true, would most strongly support the researchers’ prediction?
For “Which finding would most strongly support the prediction?” questions, restate the prediction as an if/then claim and note the required scope (who/where must be affected). Then choose the option that most directly matches both the condition (here, citywide expansion of gardens) and the outcome (a measured increase in pollinators in adjacent suburban/rural areas), prioritizing real-world before/after evidence over mechanisms, opinions, or correlations that don’t show change over time.
Hints
Clarify what is being predicted
Underline in your mind the part of the passage that states the prediction: what do Ruiz and Cho think will happen, where will it happen, and under what condition?
Match condition and result
Look for a choice that includes both the condition (expanding gardens broadly across a city) and the result (pollinators increase in adjacent suburban/rural areas).
Prefer measured outcomes over mechanisms or opinions
Mechanisms (like pollinators traveling) and opinions (like willingness to plant flowers) can help, but the strongest support will report an actual increase in pollinator abundance in the relevant areas.
Watch for weaker evidence types
Be cautious with correlations or single-time surveys; for a prediction about an increase, the strongest evidence often comes from a rollout followed by a documented change over time.
Step-by-step Explanation
Identify the prediction you need to support
Restate the researchers' prediction in your own words.
They predict that if the practice of turning vacant lots into pollinator gardens expands to the whole city, then pollinator numbers in adjacent suburban and rural areas will increase.
So the key is an outside-the-city increase that happens after citywide expansion.
Describe the ideal supporting evidence
Strong support for a prediction usually looks like a real-world case that mirrors the researchers' claim:
- the practice expands broadly (not just a few gardens), and
- pollinator abundance increases in neighboring suburban/rural areas, not only within the city.
Evaluate each choice for match in scope and strength
Check each option for (1) citywide expansion and (2) measured increases outside the city.
- Evidence that pollinators from city gardens travel into suburbs supports a possible mechanism, but it does not by itself show that suburban or rural populations increase.
- Evidence of a small pilot followed by a slight suburban increase (especially with confounds) is suggestive but weaker than evidence tied to a broad rollout.
- A cross-sectional correlation (areas near cities with many gardens have higher counts) is weaker than a before/after or rollout-linked finding because it does not establish change over time.
The strongest support will be the option that most closely replicates the prediction’s full cause-and-effect pattern.
Select the finding that most directly confirms the predicted spillover
The best support is:
- "A study of another metropolitan region found that after a widespread conversion of vacant lots into pollinator gardens, neighboring suburbs experienced a 15% increase in pollinator abundance within three years."
This matches both the condition (widespread/citywide adoption) and the predicted outcome (increased pollinators in adjacent areas), making it the strongest supporting finding.