Populi accommodates two different grading models: points-based and percentage-based. You can also include extra credit assignments and assignment groups in your grading model.

Points-based grading

Points-based grading adds up the total number of points in all of the assignments and measures the student's earned points against the total assigned points. The student's grade is then calculated using a simple ratio formula: 

Here, X is the student's final grade, which is then translated to a letter grade. This approach weights each kind of assignment equally—for example, “quiz” points would count as much as “term paper” points.

• To use points-based weighting, leave the “Other” assignment group at 100% of the weight and simply add individual assignments as needed.

Percentage-based grading

Percentage-based grading calculates the final grade by the weights you give to your various assignment groups. Each individual assignment group is first “graded” using the same ratio formula as in the points-based model:

Here, X is the student's "grade" in that assignment group. Each "grade" is then multiplied by the assignment group's portion of the final grade. The results are added together and then divided by 100, producing the student's course grade.

• To use percentage-weighting, set up Assignment Groups, dividing the “Other” assignment group's weight among your own custom assignment groups.

Here's an example

In this course, the instructor has divvied up the assignment groups as follows:

• Quizzes: 20%     Tests: 30%     Readings: 10%    Presentations: 15%    Term Papers: 25%

To arrive at the final grade, each assignment group is first given a “grade,” which is produced using the same ratio as in the points-based model:

 So, X is the student's earned points in that assignment group. Student Ben House's performance (X) in each assignment group is as follows:

• Quizzes: 90%    Tests: 80%    Readings: 75%    Presentations: 80%    Term Papers: 90%

Each value is next multiplied by the assignment group's percent-value of the final grade:

• Quizzes (90 X 20 = 1800)     Tests (80 X 30 = 2400)     Readings (75 X 10 = 750)     Presentations (80 X 15 = 1200)    Term Papers (90 X 25 = 2250)

Finally, these values are added together and the resulting sum is divided by 100: (8400/100 = 84%).

Thus, Ben House's final grade is 84%, which generally translates to a letter grade of B (depending, of course, on your school's grade scale).

Assignment points

Assignments are graded using points. When you enter an assignment grade, Populi divides it by the assignment's point total to create a percentage. The percentage is then translated to a letter grade based on your school's grading scale.

Say you have a quiz with 22 short-answer questions, each worth 1 point. When adding the quiz, you would enter “22” as the assignment's Points.

• When grading the quiz, a student gets 19 questions correct. Populi does the math (19/22 = 86.4%), which usually translates to a B or B+ letter grade.
• Another student gets 17 correct answers, and partial credit (half a point) for another question. You are allowed to enter fractional points, so this student's grade would be (17.5/22 = 79.5%) which is typically equivalent to a C+ letter grade.
• Extra credit points are also allowed. Suppose that the quiz had 4 extra credit questions each worth 1 point. Thanks to the extra credit, one student got 26 points (26/22 = 118.2%) or an A+ letter grade. The maximum extra credit allowed in the system is double the assignment's point value.

Assignment points determine the weight of each assignment within its own group, and each assignment group has a 0-100 weight for the student's overall course grade.