In the contexts of public assessment, School-based Assessment (SBA) refers to assessments administered in schools and marked by the students' own teachers. SBA marks awarded will count towards students' public assessment results.

The primary rationale for SBA is to enhance the validity of the assessment, by including the assessment of outcomes that cannot be readily assessed within the context of a one-off public examination. SBA can also reduce dependence on the result of public examinations, which may not always provide the most reliable indication of the actual abilities of candidates. Obtaining assessments based on student performance over an extended period of time and developed by those who know the students best - their subject teachers - provides a more reliable assessment of each student. Another reason for including SBA is to promote a positive impact on teaching and learning. It can serve to motive students by engaging them in meaningful activities; and for teachers, it can reinforce curriculum aims and good teaching practices, and provide structure and significance to an activity that they are in any case involved in on a daily bases, namely assessing their own students.