How Extractive Summarization Works
Extractive summarization picks sentences from the original text; it doesn't paraphrase. Three factors weight each sentence's score:
- Word frequency — sentences containing the most distinctive words (non-stop, non-rare) score higher.
- Position — first and last sentences of paragraphs tend to carry the argument. Leading paragraphs get a bonus.
- Length — very short sentences are informative but thin; very long ones dilute. Sentences 10–30 words score best.
What You Get
Sentences are scored, the top N are selected, then returned in their original order so the summary still reads as connected prose. No facts are invented because no new text is generated.
Limitations
Extractive summaries sometimes duplicate ideas (two sentences making the same point), or skip the middle where the actual argument was. For a short high-signal summary of a long article, this is usually fine. For a genuinely tight TL;DR, you may need to edit the output.