As a candidate, you will want to be informed about the assessment process you will be experiencing. Please read the document on how to prepare yourself. This page also contains examples of the main three types of tests that are commonly used for employee selection and development, giving you the opportunity to experience these tests first hand.
Becoming familiar with assessment questions can increase your score on ability tests and allow you to present yourself more accurately on personality/preference assessments.
For further information on where psychometric tests come from, feel free to visit - http://www.practicetests.co.uk