%-based vs 0-based Grading

Delphinium supports two major approaches to course grading:

  • %-based grading

  • 0-based grading

You are probably more familiar with %-based grading because it is frequently used in traditional course designs. If you are not as familiar with 0-based grading it is OK. On this page we will introduce the concepts of 0-based grading and compare them with %-based grading. We will also describe the pros and cons of each and when you might choose one over the other.

Note: It is important to recognize that both grading styles will result in the EXACT same final grade. They only differ in how they keep score during the semester. This point is illustrated in the table to the left.

%-based Grading

This chart of sample %-based grading progress displays the same data as the 0-based chart below. Notice the negative trend of the line? Earlier assignments have huge impacts on the grade while later assignments often have little impact. It is difficult to make a direct connection between assignment scores and the final grade.

Courses that use %-based grading start every student at 100% (e.g., an “A”). Each time a student submits an assignment, their % score is adjusted. Their current grade is calculated as a weighted average of all of the assignments they have submitted divided by the points possible for those assignments. For example, if a student started with 100%, then earned 50 points on a 100 point assignment, their new grade would be 50%. If they then earned 100 points on the next 100 point assignment, their new grade would be 75%. This is how most courses calculate the current grade.

The biggest pro for %-based grading is that it is familiar to students and teachers. The biggest con for %-based grading is that it obfuscates how a student's work on the most recent assignment impacts the final grade. More pros and cons are described below.

The Pros of %-based Grading Include:

  • Students typically feel like they are performing well because their % score will typically represent a "passing" grade

  • Teachers are free to adjust the point value for assignments and number of assignments at any time during the term or semester; the calculations for computing % are flexible for these types of changes

  • %-based grading is a good indicator of the quality of the work a student has turned in (e.g., a student is earning 82% of the points they attempt)

  • %-based grading is common and does not require much explanation to students

The Cons of %-based Grading Include:

  • The actual impact of each assignment on the final grade is not clear. (e.g., whether earning 90% on a 100 point assignment has any observable impact on grade depends on a complex variety of mathematical factors including current points possible and current weighted average)

  • The impact of each assignment changes over the semester. Early in the semester, poor scores on assignments can have a huge impact on the current grade, but later poor scores on assignments may have minimal impact. This makes it harder for students to respond to or predict the impact of assignments.

  • It is likely, unless students earn every point on every assignment, that the trend for their progress will be downwards

  • Submitting an assignment may not produce any visual change in the %-based score (e.g., a student could have 82% in the class, then turn in 5 assignments and still have 82%, no movement in performance is reflected). As a result, students may feel less motivation generated by submitting assignments.

  • The %-based score does not actually indicate a student's overall performance in a class if they stop working now, nor does it predict the final grade with any accuracy (e.g., What does a midterm grade of 82% say about the final grade? Nothing. The student could work very hard and raise their final to a 94%, or completely slack and end up with a 56%.)

  • Conceptually, starting a student at 100% seems to imply that a student starts a class knowing everything and the course chips away at the score until we prove the student knows less

0-based grading

This chart of sample 0-based grading progress displays the same data as the %-based chart above. Notice the positive trend of the line? Students can clearly see how their work impacts their grade.

Courses that use 0-based grading start every student with 0 points. Each time a student earns points, their point balance increases. Their current grade is calculated on a scale from 0 to max points, with grade levels assigned to various point levels. For example, in a class with max points of 1000, a D- might be 600 points, and an A might be 940 points. As students earn points, they keep a running total, starting with 0, and they progress upwards through the grade levels.

Note: Delphinium provides a default 0-based grading scale, or, if you prefer, Delphinium will use the grading scheme you configure in Canvas and the "Total Points" value from Delphinium's course settings to generate a custom grading scale for your class. 0-based grading scales are displayed as tool tips to teachers and students in the Delphinium gradebook and on some components like Current Grade. See Related Links below for details.

The biggest pro for 0-based grading is its clarity at communicating progress and the current status in the course, the biggest con is the discomfort students may feel starting the class with a failing grade. More pros and cons are described below.

The Pros of 0-based Grading Include:

  • Students always know what their final grade is if they stopped doing work now

  • Each assignment submitted results in an observable increase in the points balance, this is a motivating dynamic for many students

  • A student's grade cannot typically go down (the grade might go down if you are using milestone bonus points and a student resubmits work, or if you keep a lower grade when students redo assignments).

  • The feeling of 0-based grading is more positive, you are always moving upwards

  • Starting a student at 0 and working upwards mirrors the increased knowledge and skill the student is obtaining in the class

  • 0-based grading is similar to how games keep score and will be familiar to many students

The Cons of 0-based Grading Include:

  • Students' point value is directly tied to their grade, so they will have a failing grade until they earn 60% of the points. This can be discouraging to some students. Some of this concern can be alleviated by adding multiple levels of F for a student to pass through (e.g., adding "grade" levels at 10%, 20%, 30%, 40%, and 50% so students can observe their progress).

  • 0-based grading does not work well when the majority of the points are earned at the end of the semester, because the student will be "failing" for most of the semester, and this is discouraging

  • Teachers must lock-in the total number of points at the beginning of the course. This is difficult to do if the course is dynamic and the list of assignments are frequently changing. However, as long as the approximate total points remains the same, then there is some flexibility for adding or removing assignments or changing the point value of an assignment.

  • 0-base grading is a new concept to many students and teachers. You will likely need to train students how to do it. This will mean adding explanations in your syllabus. If you don't understand it clearly, it might be difficult to answer questions about it.

When You Might Prefer 0-based Grading

In general, 0-based grading, though new to many teachers and students, is preferable to %-based grading in many courses. The main advantage of 0-based grading is to make class progress transparent. This will help to engage and motivate students to perform better in the class. 0-based grading works well for the following:

  • Cafeteria or competency based courses where many more assignments are provided than are required to get an A grade. With 0-based grading, students can stop working when they are happy with their grade.

  • Courses that have no due dates, an even distribution of points during the semester, or that frontloads the majority of the points to the beginning of the semester. In these classes, student scores will predictably raise through the grade levels.

Combine the Stats Component with 0-based Grading

When you use 0-based grading in a course, you can overcome many of the cons by also using the "Stats" component in your course. The "Stats" component displays the "% of points earned out of points possible attempted". This value is computed similarly to how a grade is computed in %-based grading courses. Including the "Stats" component answers the question "How would I be doing if this were a traditionally graded course?"

Related Links