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It is Possible to Use Rubric Scores to Calculate Grades

download_pdf_smIn school districts measuring student success on demonstrations of learning, teachers often ask how to use rubric scores in student grades. Most often, these questions come from middle level or secondary teachers who must not only report student mastery of outcomes, but also report overall subject grades. In researching possible answers to this question, we have found that the use of rubrics is definitely advocated as a measurement tool, but there is very little discussion of ways to use the rubric score as a grade. This article will first examine the problem, then offer one solution.

When rubrics are created, the author determines a rating scale, with descriptors written for each rating. Each level of the scale describes the characteristics of a product or performance receiving that rating. The scale may include numbers, such as 1-3, or it may be defined by terms, such as Advanced, Proficient, Basic, & Beginning. These ratings are intended to describe the performance — not give it a grade. The problem arises when they are recorded as scores for the grade book, which are then calculated into a percentage or letter grade value. For instance, if the teacher communicates to students that the rubric is a 3-point scale and that a rating of 2 is sufficient to show mastery, the students will strive to receive at least a 2 rating. We assume that a student receiving a 2 is considered a strong student who has produced quality work. However, if that 2 out of 3 is recorded as a score, the percentage earned from that rating is a 66%. Most strong students would not be happy with that percentage being a part of their grade. Obviously, the problem is even more difficult when terms rather than numbers describe the scale. The tendency is to turn the terms into numbers as well, and record scores in the same way as previously described.

So what is a solution to this dilemma? While one method probably will not fit all circumstances, it might serve as a model to be manipulated into various applications. Suppose that a teacher is using a 3-point rubric scale. It is simple to determine that a 3 is a 90% or above, but those scores below it are more difficult. Is a 2 an 80% score or a 70% score? And what value is given to a 1? There is a wide range of value below 70% that could be assigned to the 1.

In order to answer these questions, some decisions must be made associated with the descriptors and the determination of mastery. First of all, if a 2 is mastery, then the student should receive a grade for that rating that represents mastery of a concept. If the district has not recommended a percentage to be associated with mastery, then the teacher will have to determine that percentage and use it consistently. In this case, a 2 might translate into an 80%. If performances or products are part of a summative assessment, as they often are, they probably should make significant impact on the calculation of a grade for the course. Therefore, a teacher could record a score of 80 out of 100 if raw scores are used, or assign any number of points to show sufficient impact, and simply find 80% of the total points. For instance, if the product is important enough that it should carry 500 points in the overall grade, then a score of 400 would be recorded for an 80%. This use of points would also allow the teacher to give percentages between 80 and 90 for those products or performances that showed some characteristics of the descriptors for a 3 and some characteristics of the descriptors of a 2 rating. Perhaps all but one of the characteristics of the product match the description of a 3. That one characteristic makes the rating a 2. The teacher could give the percentage somewhere between 80% and 90%, if that was more fair, and calculate points accordingly.

A student receiving a rating of a 1 would not receive a percentage that represented a passing grade in the class, since a 1 is not an acceptable score on this particular assessment. Again, the teacher would have to determine the percentage associated with this rating and then determine how many points the student would receive.

Students like the description of projects in terms of rubrics as they have a clear picture of the quality being sought. And while teachers find rubrics to be helpful scoring devices, they often experience difficulty in making the rubric scores useful in the calculation of a grade. This E-Hint has suggested one way to solve the problem. There is no “one right way.” The main thing is that teachers must select a method they can use consistently, and communicate that method to students. The products or performances being rated are used to evaluate the student’s success, and therefore should be included in the “grade.”