Glossary
main idea
The main idea is the central claim a passage is built to support — what the author wants you to take away, and what the other sentences exist to prove.
The main idea is the point of a passage: the one claim the remaining sentences exist to support. It is not the topic — the passage is about recycling names a subject, not an idea — and it is not the first sentence by rule. A direct opening often carries it, but a passage may open with a question, an example or the opposing view, and only then state the main idea.
Test any candidate by asking whether the other sentences are there to prove it. If they are, it is the main idea. If they are merely consistent with it, the candidate is probably too broad, and if only part of the passage supports it, too narrow.
The most tempting wrong answer is a true detail. A fact from the middle of the passage is accurate, is in the passage, and still is not what the passage is about — which is why it is stated in the passage is never the test. The stem words to watch for are mainly, primary purpose and the main point.
Taught in
Related terms
- inference — An inference is a conclusion the passage supports without stating it: one step from the words on the page, not an added fact and not your own opinion.
Source: Official ASVAB — subtest descriptions (what each subtest asks) and the CAT-ASVAB scored-question counts (accessed 2026-09)