Primary Source vs. AI Summary

Overview

AI summaries are fast and fluent, which makes them easy to trust. But a summary is only useful if it is faithful to the source. Students read a primary-source-style letter (fictional and written for this lesson) from a 13-year-old describing a flood in her town, then compare it line by line with a mock AI summary. The summary sounds right but contains six distortions: a wrong date, an exaggeration, an invented quote, an uncertain rumor stated as fact, an added detail, and a family whose help disappears. Students learn a habit historians already use: go back to the source.

Objectives

• Students will compare an AI summary with a primary source and identify at least four distortions, citing the paragraph in the source that shows each.
• Students will classify each distortion (wrong detail, exaggeration, invented, certainty added, left out, added detail) and explain why it matters to someone relying on the summary.
• Students will write a corrected summary and explain when an AI summary is and isn't a trustworthy stand-in for a source.

Step by step

1. 10–4 min

   Hook

   The telephone game, historian edition

   Ask: "Have you ever heard a story from a friend who heard it from someone else, and it changed along the way?" Take one or two examples. Say: "Historians have a rule: when you can, go back to the original. Today we'll test whether an AI summary follows that rule." Explain primary source (made by someone who was there, at the time) vs. secondary source (made later, about it). Ask: "Which is an AI summary?"

   Facilitator noteStudents often call an AI summary a primary source because it quotes the original. Clarify: it's a secondary source, written later, by something that wasn't there.

2. 24–12 min

   Explore

   Read the letter first

   Students read Handout A individually, before they see the summary. In the margin they note: who wrote it, when, what happened, what Ada was sure of, and what she was unsure of. Pairs quickly compare notes.

   Facilitator noteReading the source first matters. If students read the summary first, its version tends to stick.

3. 312–27 min

   Practice

   Distortion detectives

   Pairs read Handout B and check each sentence against the letter, using one color for matches the source and another for doesn't match. They log each mismatch on Handout C with the paragraph number and a distortion type. Key: (1) date given as May 1912; the letter is April 1911 (wrong detail). (2) "the flood destroyed the town of Willow Fork"; the letter says water reached the mill floor and the lower road, and some cellars flooded (exaggeration). (3) the quote "We lost everything" never appears (invented). (4) "caused by the new dam upstream"; Ada writes that some people say so but Papa says no one knows yet (certainty added). (5) the Castillo family, who sheltered Ada's family and rowed the books to safety, is missing (left out). (6) "a young farm girl"; her father runs the mill, and the letter doesn't say they farm (added detail). Accurate: school closed for four days; no one was hurt; the Petersons lost two cows; neighbors carried grain to the loft.

   Facilitator notePush pairs to explain why each distortion matters. Leaving out the Castillos erases who actually helped; the dam claim turns a rumor into history.

4. 427–35 min

   Debrief

   Why did the summary do that?

   Collect distortions on the board by type. Ask: "Which distortion would matter most if you only read the summary for a history project?" Then ask: "Why might an AI tool do this?" Guide students to the idea that AI tools generate likely-sounding text from patterns. Dramatic words and neat causes are common in writing about floods, so they can slip in even when the source doesn't say them. If you ran the letter through a district-approved chatbot, show that output now and check it the same way.

   Facilitator noteAvoid "AI lies." Better: "AI predicts plausible words. Plausible isn't the same as faithful."

5. 535–42 min

   Create

   Write a faithful summary

   On Handout C, pairs write a three-sentence summary that is faithful to the letter: correct date, Ada's uncertainty kept, the Castillos included. Pairs swap with another pair, who check it against the letter and mark one thing to strengthen.

   Facilitator noteLook for summaries that preserve hedges ("some people said") instead of flattening them.

6. 642–45 min

   Reflect

   My summary rule

   Each student finishes the last prompt on Handout C: "I can trust an AI summary when… I need to go back to the source when…" Collect Handout C as the exit ticket.

   Facilitator noteStrong answers name stakes: "when I'm going to quote it, cite it, or make a decision based on it."

Adaptations

Grades 3–5

Read the letter aloud and use a four-sentence summary with two distortions (the date and the missing Castillos). Students hunt with "Does the letter say that? Where?"

Grades 9–12

Pair with a real primary source from your social studies curriculum, have students run it through a district-approved tool, and write a short analysis of the distortions they find.

Emergent bilinguals

Pre-teach flood, cellar, loft, mill, rumor, and provide a picture glossary. Pairs may discuss in any language and mark the matching sentences with arrows.

Pairs well with

• Digital Inquiry Group: Civic Online ReasoningFree lessons on sourcing and evaluating evidence.
• Critical Thinking Breakouts: Signal Check, The Viral ClaimGrades 6–8 practice tracing claims to their original context.