A finding question with competing explanations tests whether evidence supports one explanation over another. Put the claim in a few words, including the cause it favors and the cause it rejects. Then ask what result would separate the two explanations. To support one cause over another, look for a comparison that changes the favored cause while keeping the other possible causes the same. A finding that both explanations predict won't settle which one fits better.
Hints
- Hint 1
Read the final sentence and separate the cause the researchers support from those they reject.
- Hint 2
In the association-based explanation, check what the caching bird needs to learn. Ask how that learning could account for a cacher moving food.
- Hint 3
For each finding, ask what changes and what stays the same. Could another cause named in the final sentence still explain why the cachers moved food?
Step-by-step
Separate seeing from the other causes
Step 1Split the claim
The final sentence says cachers must respond to the observer's specific visual access, meaning what the observer could see when food was hidden. What else might explain their moving food? The sentence lists presence, proximity, or history of stealing food, so seeing must explain the response beyond those other causes.
- Step 2
Predict evidence against the other explanation
Why isn't a barrier alone enough? The other explanation says the presence of another bird predicts later theft, so cachers could move food after learning where theft happens, without tracking another bird's view. A barrier might change both visibility and theft risk, leaving both explanations possible. We'd expect cachers to move more food after an observer saw the caches, even when presence, proximity, and theft history stay the same.
- Step 3
Test the findings against both explanations
The finding with a history of losing food links moving food to nearby birds regardless of where they face, so it doesn't separate seeing from presence. Does a larger proportion of preferred items test seeing? It compares food types instead. When observers find exposed caches more often than screened caches, learned theft risk can still explain why cachers increasingly move food.
- Step 4
Check what the shutter changes
The same nonstealing observer keeps theft history from explaining the difference, while equally near, visible, and audible means the observer stays present and at the same distance. What changed? An open shutter let the observer see the cache sites, while a closed shutter blocked its view, and cachers moved more food when it had seen the sites. Cachers move more food after being seen, even when the other possible causes stay the same, which supports the researchers' claim. Choice B.