Classification of students into bands of performance that are identified by series of cut-off scores on a performance scale. Proficiency levels are commonly used in criterion-referenced assessments For each of these levels, there should be descriptions of what it means to be in the level, in terms of knowledge, skills, attitudes, etc. Each level (or band) represents a degree of mastery of what the test purports to measure. The same levels of proficiency can be expressed with words or letters. For example, “below basic”, “basic”, “above basic”; or high, middle, low; or A, B, C.