A rubric can represent an affirmation of learner centred education. It can be used to establish a greater level of understanding and trust between the teacher and students. It can counter the notion that grading is a special secret activity. A rubric reveals the grading or scoring rules informing assessment judgements and decisions. Additionally, a rubric provides an instrument for student feedback that promotes assessment for learning. Rubrics have the capacity to clearly reveal vital information to students that enable them to improve their knowledge and skill levels.
There is no "right" answer as to how many levels of performance there should be for a criterion in an analytic rubric; that will depend on the nature of the task assigned, the criteria being evaluated, the students involved and your purposes and preferences. For example, another teacher might decide to leave off the "always" level in the above rubric because "usually" is as much as normally can be expected or even wanted in some instances. Thus, the "makes eye contact" portion of the rubric for that teacher might be
Using a rubric provides several advantages to both instructors and students. Grading according to an explicit and descriptive set of criteria that is designed to reflect the weighted importance of the objectives of the assignment helps ensure that the instructor’s grading standards don’t change over time. Grading consistency is difficult to maintain over time because of fatigue, shifting standards based on prior experience, or intrusion of other criteria. Furthermore, rubrics can reduce the time spent grading by reducing uncertainty and by allowing instructors to refer to the rubric description associated with a score rather than having to write long comments. Finally, grading rubrics are invaluable in large courses that have multiple graders (other instructors, teaching assistants, etc.) because they can help ensure consistency across graders and reduce the systematic bias that can be introduced between graders.