One advantage of a rubric is that it gives students clear directions on what is expected of them. Students will not have to guess at what is required to earn a passing grade. Students can use a rubric to keep track of their points or grades to know how well they are doing. This helps the student independently evaluate their own work.
Rubrics provide consistency in grading which makes scoring assignments more objective. The scoring is objective, because teachers do not base grades on how they feel about a student. For instance, teachers may be inclined to give passing grades to a student on a winning high school basketball team who does not work as hard as a student who is not an athlete. The teacher could decide to give the athlete a passing grade on an assignment just so she could stay on the team. Rubrics do not take into account a student's status or a teacher's subjectivity.
Just as rubrics have strengths, there are also weaknesses to using the measuring tool.
One disadvantage is evaluating students with learning disabilities. Unless a teacher retools the rubric, the measuring tool will not take into account a student's specific learning disability. Students with learning disabilities are usually working below their grade level and have challenges meeting grade level content expectations. Using a standard rubric to measure a student already below grade level may cause the student to make a poor grade in that class.
Another criticism is that rubrics focus on results and not on the process of reaching those results. Teaching merely for results stifles the creativity of students. For instance, students may want to personalize or enhance a project that is assigned to them. However, students' extra efforts to do this will not be taken into account when using a rubric. Further, students may not want to use their creativity for fear that it will work against them when measured by the rubric. Rubrics, in some cases, prevent students from thinking "outside the box," so to speak.