Judging Source Credibility

Evaluate a source by its author, purpose, evidence, and date before trusting its claims.

Before you accept a source's claims, evaluate the source itself. Four questions cover most cases. Author: who wrote it, and what expertise or experience do they have? Purpose: is the source trying to inform, persuade, sell, or entertain, and who benefits if you believe it? Evidence: does it cite data, name sources, and explain methods, or does it rely on assertion? Date: is it current enough for the topic? A source from 2005 may be fine for history but outdated for technology.

Worked example: an unsigned web page claims a supplement 'boosts memory by 300 percent,' links to no studies, and has a 'Buy Now' button on every section. Author: unknown. Purpose: selling. Evidence: none. Verdict: not credible. Compare a university study, with named researchers, published methods, and peer review. Also practice lateral reading: rather than staying on one page, open other tabs to check what independent sources say about the author and claim.

• 1Check author, purpose, evidence, and date.
• 2Ask who benefits if you believe the source.
• 3Read laterally: check what independent sources say.