History · KS3 Y8 · Working with Evidence

Cross-referencing sources

Cross-referencing sourcesFree3:36Heddy Score 3 of 7, below the standard

What you need to know

  • Circular reporting happens when one publication's claim is repeated by others and then cited back as if it were confirmed.
  • Several sources agreeing is not proof if they all go back to the same original claim.
  • A single discredited 1998 paper on vaccines spread widely because it was repeated so often.
  • To check a claim, trace it back to its original source and look for criticism of it.

In this clip

Runs 3:36, from 0:06 to 3:42 of the full video.

Also coversSources & provenance
Heddy Score3/7, Below the standard
See the seven stars
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

2.65M views · 32.6K likes · TED-Ed 23M subscribers

As reported by YouTube on 2026-11-02. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

Shows why cross-referencing only works when the sources are truly independent, a key point for checking evidence.

TED-Ed on YouTubechecked 2026-10-22

Plays from youtube-nocookie.com. No YouTube cookies until you press play.