As we describe in a related article - "How do I weight grades in Moodle?" (opens in new window) - the Moodle Gradebook is highly flexible, but because of that flexibility, it can be a bit confusing. There are multiple weighting schemes, with names whose meanings aren't always immediately obvious. In this article, we explain the most frequently used weighting schemes in Moodle, to help you choose which scheme makes the most sense for your course as a whole or for a category within your course (essays, exams, quizzes, homework, etc.).
- Mean of grades:
Best for: Category weighting scheme
Explanation: Mean of grades makes the most sense as a category weighting scheme, when all the items in the category are meant to carry equal weight. If (for example) you have 10 quizzes in a course, and each quiz is supposed to carry equal weight (regardless of their maximum point totals), then "Mean of grades" is that best weighting scheme to use for that category. Moodle will just calculate the average grade for all of the quizzes in that particular category (or, in general, all the items in that category).
- Weighted mean of grades:
Best for: Category weighting scheme and course weighting scheme
Explanation: Weighted mean of grades can be used for the course as a whole or for a particular grade category within a course. When you are using "Weighted mean of grades," you need to specify the particular weight of an item within a category or the particular percentage that a category is supposed to contribute to the overall course weight. In our Grade Weighting Help Sheet, we discuss in detail a hypothetical grade weighting situation in which essays represent 40% of the overall course grade, quizzes represent 20% of the overall grade, the final exam represents 30% of the overall grade, and participation counts for the remaining 10%. Those amounts are for demonstration purposes only, but they reveal the fact that weights are supposed to add up to 100% (using whole numbers) when you use Weighted mean of grades as your weighting scheme, and that 100% total applies to items within a category or to all the categories/items in the course. For example, if you have an "Essay" category with three essays, but the third essay is a longer, more important item, then essays 1 and 2 might be worth 25% of the category grade each (for a total of 50%), but essay 3 might be worth the remaining 50% for that category grade, equalling 100% of the total category's contribution to the course weight.
- Simple weighted mean of grades:
Best for: Category weighting scheme
Explanation: "Simple weighted mean of grades" uses the maximum point total of an item to determine its relative weight in the course. In our quizzes example, if you have some quizzes with a 10-point maximum total, and other quizzes worth 20 points, the 20-point quizzes will carry twice the weight of the 10-point quizzes. Similarly, a 50-point quiz will carry five times the weight of the 10-point quiz. Simple weighted mean of grades is called "simple" because you don't need to specify the item weights. You just need to specify the maximum point total for the item (which you do when you add the item to the course and specify its settings), and Moodle will calculate the relative weight based on that point total. When you are using "Simple weighted mean" - with point totals that determine an item's weight - you have to be careful to enter grades based on the maximum allowed value for the item. For example, if you have an assignment with a 20-point maximum value, you don't want to enter 95 into the Gradebook for an A student assignment submission. Instead, you need to enter 19 (out of that 20-point maximum total) for that A grade.
- Natural weighting:
Best for: Course weighting scheme and (occasionally) category weighting scheme. Also best for extra credit grades.
Explanation: "Natural" weighting used to be called "Sum of grades." It works best for a course with a maximum numerical total of grades, in which each item has a particular point total that contributes to that overall total. For example, if you have 500 total points in your course, and all the items together add up to that total, you would choose "Natural" weighting for your course. Like "Simple weighted mean of grades," Natural weighting uses the individual point total to determine the relative weight of each item in your course. However, Natural weighting also allows you to override individual weights, so you could assign an item a zero weight (for example) if it isn't meant to contribute to the overall point total (such as a practice quiz), or you can assign a particular percentage weight (as a whole number) for an item, as you do for Weighted mean of grades. "Natural" weighting also allows you to indicate that an item counts as extra credit only, which can work within a category or within the course as a whole.
Our Grade Weighting Quickstart Guide describes how to add items and categories to your Gradebook and how to drop grades within a category, but after that point it discusses primarily the "Weighted mean of grades" method of course grading. Please feel free to contact us via email at dps@bucknell.edu if you have questions about the Moodle Gradebook or if you'd like us to help you implement your course grading scenario within Moodle's Gradebook.