How we choose sources

The peer-reviewed paper comes first. Every article starts from a recent paper published in a peer-reviewed journal, cited in the Source box with its title, authors, journal, publication date and DOI. We may use university or journal news releases as extra sources, and we list them at the end of the article, but never in place of the paper. Where a release and the paper differ, we follow the paper and say so.

Each article shows the date its sources were last checked.

How we make corrections

When we find a factual error, or a reader tells us about one, we check it against the paper. If it is wrong, we correct the article and add a dated correction note at the end saying what changed. We make small fixes to spelling or formatting that do not change the meaning without a note.

Report an error

Please tell us through the Contact page or email adrianne+contact@mail.grokbot.com, with the page address and what you think is wrong. A link to the relevant part of the paper helps.