Grammar and reading terms · SAT Reading and Writing, ACT English, ACT Reading
Main idea
Also called: Central idea
Main idea: The central point a passage or paragraph makes, which the details support.
By the CollegePrepRoom editorial team · Updated · How we write and check these pages
What it means
The main idea is broader than any single detail and narrower than the general topic. It often appears in a topic sentence or near the beginning or end, but it may be implied.
Wrong answers on main idea questions are often too narrow (one detail) or too broad (a claim the passage does not make).
Example
Topic: urban gardens. Main idea: urban gardens improve neighborhood food access, but they rarely survive without city support for water and land.
On the exam
SAT Central Ideas and Details and ACT main idea questions test this directly.