How we correct mistakes
Report an error
Use the contact form and pick Correction as the topic. It helps if you include:
- the address of the page, or the practice set and question
- what you think is wrong
- a link to a source that shows the right answer, if you have one
How we check a report
We go back to the source the page or question cites, and to any source you sent. If the rule or figure has changed, or we got it wrong, we fix it. If two official sources disagree, we show both and say so rather than choose between them.
How corrections are shown
A correction is made on the page itself, with a short note at the end of the page giving the date and saying what changed, such as a figure updated or an explanation rewritten. When we fix a practice question, its answer, explanation and citation are corrected together.
Small fixes that do not change the meaning, such as a spelling mistake, are made without a note.
Our editorial standards
- Every question and every figure cites its source.
- We write in our own words and never copy protected material.
- Nobody can pay to change our content, questions, data or conclusions.
The methodology page explains how questions are written and facts are checked.