Interpreting Informational Text · 3 min read
Central Idea, Supporting Details, and Summary
The 5156 test asks candidates to identify, summarize, and restate a text's central idea and supporting details. These items reward the ability to separate what matters most from what simply adds interest.
Topic, Central Idea, and Details
The central idea may be stated (often in the first or last sentence of a paragraph or in the introduction) or implied, in which case the reader infers it from the details. A strong central-idea answer is broad enough to cover all the major details and narrow enough to be specific to this passage.
- Passage: "In the 1800s, Pennsylvania's canals carried coal from the mountains to Philadelphia far more cheaply than wagons could. Barges pulled by mules moved tons of cargo at once. However, canals froze in winter and could not climb steep grades. By the late 1800s, railroads, which ran year-round and crossed mountains, had replaced most canal traffic."
- Too narrow: "Mules pulled canal barges." (one detail)
- Too broad: "Transportation changed throughout history." (could describe thousands of texts)
- Best central idea: "Canals were an important but limited way to move coal, and railroads replaced them because they overcame the canals' weaknesses."
Determining Importance
To decide whether a detail is major or minor, remove it mentally and ask whether the central idea still makes sense. Major details are often marked by signal phrases such as the main reason, most important, first, or as a result. Minor details often appear as anecdotes, asides in parentheses, or vivid descriptions.
Writing an Objective Summary
A summary is a brief, objective restatement of a text's central idea and key supporting points, in the reader's own words and in the original order of importance. A paraphrase restates a short passage in about the same length; a summary condenses.
| Feature | Strong summary | Weak summary |
|---|---|---|
| Length | Much shorter than original | Nearly as long; retells everything |
| Content | Central idea + key points | Minor details or one section only |
| Language | Reader's own words | Copied phrases |
| Viewpoint | Neutral | Adds "I think" or evaluation |
Finished reading?
Lock it in with a quick Interpreting Informational Text quiz.