What is 'evidence'?

Good evidence comes from objective, unbiased research that follows well-recognised ethical, statistical and scientific criteria.  It is usually only found in peer-reviewed articles published in recognised quality scientific journals.  Where an opinion is provided based on evidence, the author should reference that opinion with the relevant article.  All evidence-based facts published on this website include such references.  This enables the reader to easily find the article and read it and check it for themselves.

Some guidelines are included on the following pages to help you understand the simple statistics presented in studies, types of studies, and how they can be graded.