This chapter reviews the literature on self assessment and focuses on the comparison of student-generated marks with those generated by teachers. Studies which include such comparisons in the context of higher education courses are reviewed. The chapter is concerned to address the following questions: do students tend to over-or under-rate themselves vis-a-vis teachers? Do students of different abilities have the same rating tendencies? Do students in different kinds or levels of course tend to under-or over-rate themselves? Do students improve their ability to rate themselves over time or with practice? Are the same tendencies evident when self-marks are used for formal assessment purposes? And, are there gender differences in self-rating?