A list of requirements against which a piece of work or the performance of a task is measured in order to judge whether it has been successfully completed. An assessor will use assessment criteria in order to distinguish between work which is a pass and work which is a fail, and in order to determine what percentage or category of mark to award. The purpose of such criteria is to ensure a degree of objectivity in the forming of an assessment decision. They may be devised and employed within one awarding institution, such as a university; or, in the case of work leading to national awards, they may be devised and imposed externally by a national awarding body. In all cases their purpose is to support the standardization and reliability of assessment decisions. See also grading criteria.