The assessment of a piece of student work by two teachers in order to ensure that the mark or grade awarded is accurate and reliable. It is a process which is most valuable when the assessment method is vulnerable to some degree of subjectivity on the part of the marker; for example, in the assessment of essay‐style answers or longer pieces of student work such as written assignments and dissertations. The second marking may be carried out as ‘blind’ marking, which means that neither teacher sees the comments or assessment decision of the other prior to arriving at their own decision. Alternatively, the second marker may have access to the first marker's comments and the grade or mark awarded. Second marking, or double marking, is an important feature of assessment in courses where the student outcome depends wholly or heavily on continuous assessment. See also moderation.