Corrections policy

Last updated September 30, 2026.

Reporting an error

If you believe an article, quiz question or explanation contains a mistake, please write to us through the contact page (choose “Correction request”) or send an email to [email protected]. It helps if you include the page address, the sentence or question in doubt and, if possible, a source that shows the correct information.

How we handle reports

1. We read every report and check it against the sources used in the article and against additional reliable sources.
2. If the report is correct, we fix the content.
3. If the report is not correct, we keep the content and, when useful, clarify the wording so the point is easier to understand.

Types of corrections

• Minor edits such as typos, grammar and formatting are made without a note. The “last reviewed” date is updated.
• Substantive corrections that change a fact, number, date or conclusion are fixed in the text and marked with a correction note at the top of the article describing what changed and when.
• Quiz questions with an incorrect answer, an ambiguous question or a weak source are corrected or removed as soon as we confirm the problem. Questions in the same article are rechecked as well.

Corrections log

No substantive corrections have been issued since the site launched on September 30, 2026. Any future corrections will be listed here with their date.

Sources that change

Web pages move or disappear. If a cited source becomes unavailable, we replace it with an equivalent reliable source and update the review date.