This comparative overview is based on information provided directly by the test providers themselves. We wrote to each provider and invited them to supply details of their test, covering its design, content, delivery, scoring, and published research. Their responses have been compiled into a common framework to allow comparison across tests.

We will review this framework regularly to keep it accurate and up to date, and we will also update individual entries when test providers notify us of changes to their test. If you are a test provider and would like to request a review of your entry, please contact us.

This overview is provided as a factual resource and does not express a preference for any particular test.