Calculating Grades with Rubrics

Determining Numeric Scores from Analytical Assessment Tools

Jan 9, 2009

Analytical rubrics are ideal for skills assessments but can be adapted to provide a traditional numeric grade.

Analytical rubrics are becoming an assessment tool of choice for many teachers. Though related to holistic rubrics by their descriptive nature, analytical rubrics go further into describing the criteria necessary for student success by adding qualities such as novice, basic, proficient and advanced. Whereas holistic rubrics focus on one major category of skills and provide a quantifiable grade for the assignment, analytical rubrics can cover more categories and be difficult to use to determine one meaningful numeric score for the entire assignment.

Converting Qualities to Quantities

One way to calculate an assignment grade is to assign each quality a value, such as novice is worth one point, basic worth two, proficient three and advanced four. If there are ten criteria for the assignment, then the grade is the sum of points earned divided by forty. If the goal is for students to be proficient and an advanced assessment is considered extra credit the divisor would be thirty. This version is essentially a holistic rubric with extra detail.

Raymond W. Lee of Harding University suggests a different approach. Lee recommends determining a grade range for each quality, possibly even for each criteria. This can then be adapted to a final numerical grade either by category or for the entire assignment. If this method is used, Lee advises to make sure to determine the scale in advance not only so students understand it but also so the teacher can later use the rubric to support the grade.

Adapting Scores to Reflect Emphasized Skills

Since analytical rubrics are designed to provide detail, descriptive assessments of a student’s exhibited skills on a given assignment they do not easily lead to one meaningful grade for all students. For example, if a rubric for a book report has criteria for accurate spelling and for identifying the conflict in the story one student might do very well identifying the conflict but has many spelling mistakes while another student could not identify the conflict but had no spelling errors. Would the two students receive the same grade?

When skills are to be evaluated with different emphasis then the teacher should determine a separate score or multiplier for each criterion. This might mean that both criteria are evaluated as a possible score of 1, 2, 3 or 4 , but then spelling is kept as that number and identifying the conflict multiplied by 3 to show that being able to identify the conflict in the story is the focus of the assignment.

When converting the skill assessment to a numerical grade it is most important that the teacher doing the grading is comfortable with the method used. This results in more consistent grading practices by the teachers and a better understanding of the assessment by the students.

“Scoring Performance Assessments.” Alabama Professional Development Module, Alabama Department of Education.

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