A finding question tests whether evidence backs a prediction comparing groups over time. Read the prediction and put the claim in a few words: what changes, what result is measured, and which groups are compared. Then check what the study measured and how it compared the groups over time. The groups must start alike in other important ways, or those differences could explain the result. Evidence about a related result still may not support the result the prediction names.
Hints
- Hint 1
Put Vega’s final prediction in a few words, including the result, the time span, and the two planting methods.
- Hint 2
Look at the sentence about the spaces between clusters. How do those spaces matter to Vega’s use of continuous in the final prediction?
- Hint 3
Connect Vega’s explanation to her prediction. What would you need to measure about wave energy, sediment, and rhizome growth to test that explanation alongside her prediction about cover?
Step-by-step
Test the whole prediction
Step 1Pin down the comparison
Vega predicts more continuous vegetative cover over several years on erosion-prone shorelines. Since we’re supporting that prediction, what comparison must the finding show? Starting with the same number of shoots, clustered planting should produce more connected cordgrass cover than uniform spacing does, so the result is shoreline cover over time.
- Step 2
Predict the full test
What would make the cover continuous? Vega links capture sediment to making the intervening gaps suitable for cordgrass rhizomes to enter, so cordgrass must spread between the clusters. Rhizomes are underground stems; their spread should follow sediment buildup, and we must measure the gaps to see that spread. We also need shorelines that start alike, or the sites could explain the later difference.
- Step 3
Find what’s missing
Check the findings against more continuous vegetative cover over several years. Do they compare whole shorelines fairly? Reporting cover only after combining results hides whether clustered plots beat uniform plots. The before planting sediment difference means the sites could explain the later advantage, because clustered sites already gained sediment faster. And frames centered on the original clusters leave the intervening spaces unmeasured, so they can’t show whether the shoreline filled in.
- Step 4
Use the outcome and its timing
The finding with less bare shoreline after five years shows more continuous vegetative cover over several years on comparable sites with equal shoot numbers. Its lower cover in year one fits Vega’s warning about competition. Gap elevation rises before rhizomes enter, which supports sediment buildup making gaps suitable for plant growth. Choice D.