In-depth practical guides

Assess the independence of multiple sources

Count original records rather than links: identify republication, shared data and distinct observations before drawing a conclusion.

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Reading room of the John Rylands Library in Manchester, photographed in 2016.

Reading room of the John Rylands Library in Manchester, photographed in 2016. Documentary context photograph; it does not depict an Alexis Roux ZG assignment or equipment. © Michael D Beckwith · Source · CC0. Resized and converted to WebP; cropped display.

Do two websites really confirm a fact twice?

Domains, logos and formats do not establish independence. Several outlets can reuse a press release, and a registry can feed both a portal and an API. Evaluate one precise claim: documents may have independent commentary while relying on the same figure. The output is a map of origins with remaining uncertainties.

  1. Split the claim

    Separate identity, date, amount, attribution and consequence. Retain the supporting passage for each element. One page can be primary for a statement and secondary for an estimate.

  2. Trace the original record

    Follow links, references, document numbers and producer details. Distinguish author, distributor and index. Stop at an identified document, not a search engine.

  3. Compare documentary features

    Match identifiers, versions, figures, wording and files. Unusual agreement can suggest republication but does not alone prove copying. Seek explicit attribution.

  4. Classify relationships

    Distinguish the same record, the same collection, new analysis of shared data and a distinct observation. Mark undocumented lineage as unknown rather than inventing a connection.

  5. Seek a useful contradiction

    Try another collection method, event or producer. Differences may come from scope or time; compare definitions before selecting a version.

  6. State the conclusion

    Describe original records supporting each claim and what agreement establishes. Matching portals can check transcription without providing independent observations.

Situations and decisions

Typical situations for preparing a check. They do not describe completed assignments or actual observations.

One decision, two portals

CNIL also publishes decisions on Légifrance. Match number, date and text; an identical decision counts as one record with two access paths.

One work, multiple indexes

OpenAlex documents inputs from Crossref, DataCite and PubMed. Match DOI and version; another record may improve discovery without adding a scientific experiment.

Republished press release

Find the original statement. A reporter may contribute an investigation: attribute declared and independently checked facts separately.

Record to retain

  • Atomic claim, excerpt and original record identifier.
  • Author, data producer, distributor and consulted index.
  • Documented relationship, supporting link, version and date.
  • Unknown origin, remaining contradiction and resolving check.

Official references

Related source profiles

Related protocols

Checks before reaching a conclusion

  • Does every confirmation identify an original record?
  • Are shared documents separated from new collection?
  • Are undocumented relationships still marked unknown?

Frequently asked questions

Are different news outlets independent?

Not necessarily for the claim. Check whether they share a press release, witness or dataset.

Is a translation another source?

It is another language version of the same original document. Check the translation separately.

Are two sources always needed?

A number alone is insufficient. Use records competent for the question and disclose a single origin’s limits.