Quick Reference 7: Main Point and Supporting Detail

Reference 7: Main Point and Supporting Detail

Both statements below each passage are accurate. Only one of them is what the passage is actually about. Correctness is necessary for a main-idea answer. It is never sufficient on its own.

A city’s bike-share program added two hundred new docking stations last year, all installed in neighborhoods more than a mile from the nearest subway stop. Ridership in those neighborhoods more than doubled. Citywide, the numbers suggest that placement, not overall size, decides whether a bike-share system actually gets used.

True detail: The city added two hundred new docking stations last year.

Whole point: Where a station is placed matters more than how many stations exist.

A species of orchid produces flowers that mimic the appearance and scent of a female wasp closely enough to draw males in for a failed mating attempt. The orchid offers no nectar, no pollen, nothing but the deception itself. Its entire reproductive strategy depends on convincing an insect that a false signal is real.

True detail: The orchid’s flowers mimic the appearance and scent of a female wasp.

Whole point: The orchid reproduces by deceiving an insect into acting on a false signal.

A manuscript translated from Old Norse in the 1920s used the word “luck” wherever the original carried a narrower sense, closer to the specific fortune owed to one family line. A reader who takes the translation at face value misses an entire belief system folded into a single mistranslated noun.

True detail: The 1920s translation used “luck” for a narrower original term.

Whole point: A single mistranslated word can hide an entire belief system from a reader.

During a record heat wave, a regional power grid avoided rolling blackouts by asking large industrial users to voluntarily cut consumption during peak afternoon hours. Residential demand that same week hit an all-time high. The grid held not because total demand fell, but because the reduction arrived exactly when the system was most strained.

True detail: Residential demand hit an all-time high that week.

Whole point: The grid held because the reduction arrived at the moment of peak strain, not because total demand fell.

Before choosing a main-idea answer, ask what the rest of the passage would have no reason to exist for, if this one sentence were the whole point.