For a data-based command-of-evidence question, break the claim into its separate parts and identify what the data must demonstrate for each part. Here, compare cumulative coverage, maximum coverage, continuity across periods, and brood production. Favor the choice that controls the competing explanations and supports the predicted relationship most completely.
Hints
- Hint 1
Separate the possible predictors
The prediction contrasts steady floral availability with both cumulative coverage and the largest coverage value in one period.
- Hint 2
Compare totals and distributions
Add the three coverage values for each lot, and then examine how evenly each total is distributed across the season.
- Hint 3
Look for the strongest controlled comparison
Find the choice that holds cumulative coverage constant while connecting the absence of a low-coverage period to brood production.
Step-by-step
- Step 1
Identify the predicted relationship
The researchers distinguish continuity from two alternatives: cumulative coverage across the season and the highest coverage reached during one period.
- Step 2
Compare the coverage patterns
The three coverage values sum to 93 for every lot. However, only North avoids a sharp seasonal shortage, remaining near 30 during all three periods.
- Step 3
Connect the pattern to brood production
North recorded 8.2 successful brood cells per nest, compared with 3.5, 3.8, and 4.1 for the other lots. Because total coverage is held constant and North does not have the highest single-period coverage, the data most directly associate greater brood production with steady floral availability.