Updated 11-22-2011
Moodle grade book guidelines
The following are guidelines in setting up the Moodle grade book and points to keep in mind as
you use the grade book. Your specific course may be different depending on how you calculate
your grades. A few things before we look at specifics.
As you work through the grade book, make sure that the “extra credit” box is not checked on a
grade item or category. Grades higher than 100% can already be entered in the grade book.
Checking the “extra credit” box means that item or category is not included in the course total
(throwing off the calculations).
Depending on the aggregation method that you select, grade items that have not been
attempted are not counted in the grade. The way that Moodle handles this is that the course
total that is shown for the student may not actually be the number of points that they have
earned. It reflects the number of points that they would have (compared to the total number
of points possible in the course) to give them the percent grade that they have at that point.
That is, if a student had 403 points out of 500 (80.6%) and you added a 10 point assignment
that they have not attempted, then the Moodle grade book would show that student as having
411.06 points and still have a grade of 80.6%. That is because 411.06 divided by 510 (the new
course total) is 80.6%. For this reason, it will be important to stress with the students that the
course total number is artificial and that it is the percent grade that they (and you) need to
keep in mind.
Items that have been hidden (in the grade book or on the course page) will not show up in the
grade book that the student sees, unless you change settings in gradebook. Course and
category totals that are hidden in the grade book will not appear in the student grade book,
unless you change settings in gradebook.
Teachers will have control (in the grade book settings) to determine how that grades are
displayed. Regardless of what you choose, students, by default, will always see at least a
percent in their grades area. A setting of “real” will display points only. A suggested display is
“percentage”. You may want to have the display set to “real(percentage)” as you develop the
course and setup your gradebook.
Always make sure that the course total correctly reflects the total number of points that are
possible for the course. You may need to set the aggregation to “sum of grades” temporarily so
that the Moodle grade book will calculate the total (you can enter this number manually, if you
wish).
Setting up Aggregations
Mean of grades
In some courses, the
number of points (or
marks) given to an
item is arbitrary and
is not a factor in
deciding its weight in
computing the
course grade. With
this grading strategy,
one would first
convert each item
to a percentage
value and then
average the
percentages in
computing the
course total.
Moodle calls
this Aggregation met
hod of computing
grades Mean of
grades because the
average is
computed giving
the same weight to
each item.
The sum of all grades
divided by the total
number of grades.
A1 70/100, A2
20/80, A3 10/10,
category max 100:
(0.7 + 0.25 +
1.0)/3 = 0.65 -> 65/100
Weighted mean
In many courses, the
instructor may want
to assign different
elements of
performance (such
as daily work and
tests) to defined
percentages in
determining a
course grade.
Moodle calls
this Aggregation me
thod of computing
course
grades Weighted
mean of
grades because the
course grade is
computed by
weights that the
teacher assigns to
categories (or
items).
Each grade item
can be given a
weight, which is
then used in the
arithmetic mean
aggregation to
influence the
importance of
each item in the
overall mean.
A1 70/100 weight
10, A2 20/80
weight 5, A3 10/10
weight 3,
category max
100:
(0.7*10 +
Simple weighted mean
By default, Moodle
computes a course
grade based on the
total number of
points (or marks)
earned, divided by
the number of points
possible.
Moodle calls
this Aggregation met
hod of computing
course
grades Simple
weighted mean of
grades because
items are weighted
based simply on
their maximum point
value.
Note that items are
not computed into
the grade until a
score is assigned.
This means that you
can post your
activities as far in
advance as you
wish; students
always see a grade
based only on what
has been marked.
You can change this
to have all nongraded items
counted as a zero if
you wish.
0.25*5 +
1.0*3)/18 =
0.625 -->
62.5/100
Mean of grades (with extra
credits):
Arithmetic mean
with a twist. An
old, now
unsupported
aggregation
strategy provided
here only for
backward
compatibility with
old activities.
Sum of grades
The sum of all
grade values.
Scale grades are
ignored. This is the
only type that
does not convert
the grades to
percentages
internally
(normalisation).
The Maximum
gradeof
associated
category item is
calculated
automatically as a
sum of maximums
from all
aggregated
items.
The difference
from Weighted
mean is that
weight is
calculated
as Maximum
grade - Minimum
grade for each
item. 100 point
assignment has
weight 100, 10
point assignment
has weight 10.
A1 70/100, A2
20/80, A3 10/10,
category max 100:
(0.7*100 +
0.25*80 +
1.0*10)/190 =
0.526 -->
52.6/100
Mode of grades
The mode is the
grade that occurs
the most
frequently. It is
more often used
for non-numerical
grades. The
advantage over
the mean is that it
is not affected by
outliers (grades
which are
uncommonly far
from the mean).
However it loses its
meaning once
there is more than
one most
frequently
occurring grade
A1 70/100, A2
20/80, A3 10/10:
70 + 20 + 10 =
100/190
Median of grades
The middle grade
(or the mean of
the two middle
grades) when
grades are
arranged in order
of size. The
advantage over
the mean is that it
is not affected by
outliers (grades
which are
uncommonly far
from the mean).
A1 70/100, A2
20/80, A3 10/10,
category max 100:
median(0.7 ;
0.25 ; 1.0) =
0.7 --> 70/100
Smallest grade
The result is the
smallest grade
after
normalzation. It is
usually used in
combination
with Aggregate
only non-empty
grades.
A1 70/100, A2
20/80, A3 10/10,
category max
100:
min(0.7 ; 0.25
; 1.0) = 0.25 -> 25/100
(only one is kept),
or when all the
grades are
different from
each other.
A1 70/100, A2
35/50, A3 20/80,
A4 10/10, A5 7/10
category max 100:
mode(0.7 ; 0.7
; 0.25 ; 1.0 ;
0.7) = 0.7 -->
70/100
Highest grade
The result is the
highest grade
after
normalization.
A1 70/100, A2
20/80, A3 10/10,
category max 100:
max(0.7 ; 0.25
; 1.0) = 1.0 -> 100/100
For calculating grades where the final grade is points earned divided by the total possible
points……
Set each grade item up with the appropriate maximum grade and select “simple
weighted mean of grades” as the aggregation (if not using categories).
If using categories, set each grade item up with the appropriate maximum grade in the
selected category. Set each category up as “simple weighted mean of grades” and select
“simple weighted mean of grades” as the course aggregation. Also, in “full view”, make sure
that “aggregate only non-empty grades” is checked for each category.
If choosing to drop a grade from a category, choose “full view” in grade book, and select the
number of items to drop from that category from the “drop the lowest” column.
Uncheck “Aggregate only non-empty grades” for the course.
Don’t forget to save changes.
For calculating weighted grades, set the grades up in categories. Change all categories and the
course aggregation to sum of grades to make sure that the course total is correct.
Set each category to “simple weighted mean of grades”.
Set the course aggregation to “weighted mean of grades” and enter the desired weight by each
category.
Switch to full view. Check “Aggregate only non-empty grades” for the course and for each
category.
Uncheck “Aggregate including subcategories” for the course and for each category.
Don’t forget to save changes.
For calculating grades where a mean of grades is used (each grade converted to a percent and
then averaged)…..
Set each grade item up with the appropriate maximum grade and select “mean of
grades” as the aggregation (Do not use categories).