Educators began writing down the values and criteria they had been using in their minds. A student's work may be judged on the level of competency related to each of these criteria. The description of each level of a criterion is called a rubric. In education, rubric has come to mean a chart, a matrix with criteria on one side and levels of sophistication in attaining each criterion along an adjacent side. These levels may be assigned scores and weights.
Graduated descriptions create a scale, a continuum of competence.
The top rubric of the scale equals the 'standard' for that criterion. This definition is not universally accepted. Students I once worked with prefer more levels to less levels. I agreed, and a fourth level with attendent rubrics was added. The student takes responsibility for her own inquiry after setting workable goals.