Assessment describes a broad range of practices from informal evaluations of student learning and progress to formal summative examinations for the attainment of recognised qualifications such as NCEA. Assessment can be both formative, which means that it is used to inform ongoing teaching and learning, and summative, which is used to provide a measure of learning and progress. However, this is not a fixed distinction, as summative measures can also be used to inform the focus and direction of future teaching and learning. Sound educational assessment is characterised by validity, reliability and fairness in all assessment practices.