Assessment of learning assists teachers in using evidence of student learning to assess achievement against outcomes and standards. Sometimes referred to as ‘summative assessment', it usually occurs at defined key points during a unit of work or at the end of a unit, term or semester, and may be used to rank or grade students. The effectiveness of assessment of learning for grading or ranking depends on the validity and reliability of activities. Its effectiveness as an opportunity for learning depends on the nature and quality of the feedback.