How do teachers determine letter grades and GPAs from standards? (Standards-Based Grading)

The purpose of standards-based grading/reporting is to communicate students’ current strengths and areas for improvement relative to course or grade-level standards. It may seem counter-productive to “go back” to using letter grades once a student’s level of learning has been described using an integer scale (i.e. 1-4) with corresponding descriptions of learning. Because some secondary schools may have a need to determine letter grades and grade point averages, the purpose of this post is to describe several ways to make this happen. The first step is to determine a standard score. The second and final step is to determine a final grade based upon the standard scores using one of three methods. In other words, a secondary school using standards-based grades does not need to fully eliminate reporting letter grades, if there is a compelling reason to do so.

Determining a standard score (level of learning)

No mathematical formulas are needed to determine a student’s standard score. Let’s consider Tyler, a student who has a “3” level of learning (demonstrates understanding with minor errors) right now in the grade book for a high school math standard, “Represent data with plots on the real number line” (HSS.ID.A.1). After working with the teacher to complete a re-learning plan, Tyler completes a new assessment on data plots. His teacher determines that he now has a “4” level of learning (demonstrates proficient understanding of the standard). Because we want to communicate Tyler’s current level of learning, the teacher would erase the 3 in the grade book and replace it with a 4 rather than averaging these two attempts.

Determining a letter grade based upon the standard scores

In my experience and observation, schools have used one of three methods when converting standards to letter grades in a standards-based grading environment. I will explain each one in detail below using the following fictitious grade book, which we’ll assume represents a student named Cassy’s level of learning in math near the end of a reporting period.

[Cassy’s level of learning in math near the end of the reporting period (sample)]

Convert to Percentages Method
In order to determine a letter grade using the convert to percentages method, use the following steps:

  • Add up all of the standard scores.
  • Divide it by the total number of standard scores possible.
  • Use the school’s typical 90%, 80%, 70%, etc. percentage scale to determine the letter grade.

Using Cassy’s math standards and levels of learning above, she currently has 34 standard scores (4+4+3+4+4+4+4+2+4+1). The total number of standard scores possible is 40 (4 scale x 10 standards). Using a typical 90, 80, 70, 60 scale, Cassy has 85% (34/40=85%), therefore her letter grade would be a B using the percentages method.

The convert to percentages method will work with many electronic grade books and likely makes sense for parents and students who are used to a points/percentages grading system. At the same time, this method has a “points and percentages” feel to it which is less-than-ideal for communicating student learning in standards-based grading.

Marzano Method

This method of determining letter grades comes from literature written by Robert Marzano and his colleagues. In order to determine a letter grade using the Marzano Method, use the following steps:

  • Average the standard scores.
  • Apply the following conversion scale
[Source: Marzano, R. J. (2010) Formative assessment & standards-based grading. Bloomington, IN: Marzano Research Laboratory.]

Using Cassy’s math standards and levels of learning, her average is 3.4 (34/10). Based upon the conversion scale above, her letter grade would be an A.

It is important to know in Marzano’s writing, “4” often describes learning exceeding the standard rather than proficient, a distinction I recommend reading about in a write-up by Dr. Thomas Guskey here. This may explain why a student with an average of 3.0 to 4.0 receives some flavor of an “A” while a student must have an average of 2.5 to 2.99 to earn some type of a “B” in this scale.

I am also not sure how many electronic grade books will determine a letter grade using the Marzano method, therefore manually overriding final letter grades may be necessary.

Logic Rule Method

In order to determine a letter grade using the logic rule method, use the following steps.

  • Determine a logic rule for your classroom / school
  • Count up the number of 4s, 3s, 2s, 1s, etc. currently in the grade book.
  • Apply the logic rule.

The following logic rule is adapted from Ken O’Connor’s book How to Grade for Learning, 4th edition. This is only a sample and could be revised (for example) to communicate plus and minus grades.

A = Student has demonstrated level 3 and level 4 understanding for all standards with a majority of 4s. No standard scores are below 3.
B = Student has demonstrated a mix of level 3 and level 4 understanding for all standards with a majority of 3s. No standard scores are below 3.
C = Student has demonstrate a mix of level 2, level 3 and level 4 understanding for all standards with a majority of 3s. No standard scores are below level 2.
D = Student has demonstrated a mix of level 2, level 3 and level 4 understanding with a majority of 2s. No standard scores are below level 2
F = Student has at least one standard score of 1 or 0.

Using Cassy’s math standards and levels of learning, she has a “1” right now on the standard “Use data from a sample survey to estimate a population mean…” therefore her letter grade is an F. At first glance, this particular logic rule may seem harsh, however it should be noted that students are provided multiple opportunities to demonstrate understanding in standards-based grading, therefore Cassy is has ample opportunity to improve based upon supports provided by the teacher.

Few, if any major electronic grade books currently can determine a letter grade using a logic rule, therefore the teacher would need to manually override the letter grade.

Calculating a grade point average using standards-based grading

Calculating a grade point average (GPA) in standards-based grading follows the local school guidelines, likely similar to when the school previously used points and percentages to determine letter grades. Once a letter grade has been determined from standard scores using one of the methods described above for each course, a grade point average can be calculated for honor roll and/or high school transcript purposes.

Closing Thoughts

Because some secondary schools may have a need to determine letter grades and grade point averages, the purpose of this post was to describe several ways to make this happen. School leaders should consider the pros and cons of each standard score to letter grade conversion method when making a local determination for their building or district.

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