Supporting Details

Supporting details are phrases, sentences, or paragraphs that help strengthen your understanding of the main idea. Much of what you read includes minor details, items that are less important in helping you determine the main idea of a passage. Judging which details are the most important, or relevant, means asking yourself the question, Does this detail help me identify the author's meaning? If you can answer yes, then the detail is a relevant, or supporting, detail.

Example

This short paragraph uses details to lead to the main idea.
       The world of the gods in ancient Greek myths was pleasant, not fearful. True, the gods of Mount Olympus were unpredictable. One never knew when Zeus would send down his thunderbolt. But, for the most part, the Greek gods did not inspire great fear, because they looked and behaved like human beings. Unlike the cold and terrible beast gods of ancient Egypt, with their cat's heads and eagle's claws, the Greek gods were radiantly beautiful. Unlike the grim gods of Norse mythology who brooded and battled constantly, Zeus, Apollo, and Aphrodite were more interested in eating ambrosia, playing music, and falling in love.
The main idea is that the mythological world of the Greek gods was pleasant rather than frightening. The second and third sentences do not support the main idea—certainly, having Zeus strike you with a thunderbolt would be frightening. The fourth, fifth, and sixth sentences, however, do support the main idea by telling why the Greek gods did not inspire fear: the gods looked like humans, not beasts; they were beautiful; and they engaged in pleasant activities.

See pages 23–30 in Contemporary's GED Language Arts, Reading for more information on supporting details.