A main idea question about a study tests whether you can say what the findings show together. Start by naming the topic, then find the point after a shift from an earlier view. If researchers make a change, ask what they learned from its results and from any later test. Predict one sentence that connects those findings, not a list of what the researchers did. An answer can be true about one result and still leave out the main point.
Hints
- Hint 1
The passage shifts from simulations to a field trial at But. What happens in the field trial?
- Hint 2
Trace the software change through its results. What does the text report about outlying passengers’ waits and the system’s productivity?
- Hint 3
Put the trial’s problem and the results of the software change into one sentence. How does the final simulation help you understand that finding?
Step-by-step
Connect the problem and the fix
Step 1Find what the trial reveals
Cities judge minibuses by riders served per vehicle-hour, but a main idea must include what the trial shows about that score. What happens when requests cluster at stations? The text reports, “Productivity stayed high, yet passengers in outlying neighborhoods experienced erratic waits.” So the overall score hides uneven service.
- Step 2
Build a prediction from the change
Does the fix improve those waits, and at what cost? After capacity was reserved for requests away from stations, outlying passengers’ wait times became more consistent, while the system retained nearly all its earlier productivity. Our prediction needs to say what went wrong and how the team fixed it: high productivity can hide uneven waits, but a focused software change can steady them without losing much productivity.
- Step 3
See what the final test adds
Why add the simulation where requests were evenly distributed? The reservation rule is rarely used there and changes almost nothing, so the final test shows when the fix matters. It adds to what the trial shows about clustered demand, but the uneven waits and the team’s fix are still central.
- Step 4
Choose the full finding
Field evidence qualifies productivity-based assessments leaves out the fix, while A capacity-reservation rule is most useful narrows the point to when the rule helps. The call to prioritize consistent access adds a priority the team never states. An overall productivity measure can conceal uneven service connects the hidden problem to the successful adjustment. Its most productivity matches retained nearly all its earlier productivity, without claiming there was no loss. Choice C.