Cited & Contested · Free printable

The source-evaluation guide

A number arrives with no parents. This is how to work out where it came from and how much weight it can carry, in about a minute.

Six questions to ask a source

  • Who made this, and what do they do all day? A statistics agency, a regulator, a university, a newspaper, or a company selling the thing being measured. Each exists for a different reason.
  • Who paid for it? Funded research is often good research with an interest in the answer. The funding should be findable.
  • Is this the original, or a report about the original? Reporting is a map to the source. It is not the source.
  • What was measured, and over what period? Averages hide their range, and a start date chosen well can carry an argument on its own.
  • Can I reach it? If you cannot open the document, you are trusting a summary. That may be fine, if it is a conscious choice.
  • Does anyone credible disagree, and on what grounds? One search for the strongest objection beats five searches for agreement.

How much weight each kind of source can carry

Kind of sourceGood forWatch out for
Statistics agencies and regulatorsRules, rates, thresholds, measured aggregates.Definitions that differ from everyday usage, and later revisions.
Peer-reviewed researchWhether an effect exists, and how big.Who was studied, how long ago, and whether the press release matches the paper.
Primary documentsFees, terms, filings, what a product actually is.Length and deliberate dullness. The important sentence is rarely first.
Published comparisons with a stated methodLong-run patterns across many products.Who selected the sample, and what left it.
Reputable journalismFinding the primary source, and context.Headlines written by someone who did not read the study.
Industry researchData nobody else collects.An interest in the conclusion. Read the method first.
BooksArgument, framing, teaching.Being cited as evidence for themselves.
Anecdote and testimonialIllustrating an idea.Being counted as evidence that the idea works.

Seven warning signs

  • A percentage with no denominator.
  • Studies show, with no study named.
  • A chart that starts its timeline at a suspiciously good year.
  • A round number that appears everywhere and traces back to nothing.
  • Survivor stories used as proof, with no mention of the people who did the same and failed.
  • The word guaranteed anywhere near the word returns.
  • Urgency. Real evidence is still true next week.

Free to print, copy and hand out with attribution. From citedandcontested.com. Educational commentary only, not financial advice.