Editorial standards

Brainlag is a small independent study website run by one person. This page explains how its content is written and checked, and what to do if you find a mistake.

Who writes it

Everything on Brainlag is written for Brainlag. Brainlag is independent: it is not affiliated with or endorsed by any exam board (AQA, Pearson Edexcel, OCR, WJEC Eduqas, CCEA, SQA, ABRSM, Trinity College London or any other), and the names of exam boards belong to their owners.

Sources

Topics and specification references come from the exam boards' own published specifications.

Exam dates come from the boards' published timetables, and past papers and mark schemes are links to the boards' own websites. Brainlag does not copy past papers.

Science data uses standard published values, for example IUPAC standard atomic weights in the molar mass calculator. Where a data sheet rounds differently, the page says so.

How content is checked

A calculator page that shows "Formulas and worked example checked" with a date had its formulas compared with the specifications they come from, and its worked example worked through by hand, on that date, in every language it is published in, with the same numbers.

Revision notes list where each topic sits in each board's specification, so you can check it against your own course.

Questions in Brainlag Learn are original. Answers and mark schemes are only shown after you try a question.

Grades are estimates

Any grade a Brainlag tool or course shows is an estimate. Grade boundaries are set by the exam boards and change every year, so no website can promise a grade.

Ads and Plus

Ads and Brainlag Plus pay for the free part of the site. Advertisers have no say in what the pages teach.

Found a mistake?

Email [email protected] with the page address and what looks wrong. Confirmed mistakes are fixed, and a calculator page gets a new checked date when it is checked again.