Relative Assessment grade – another form of feedback

A student receives their grades from each assignment along with their feedback. However unless the lecturer posts a list of student grades publicly the student has no idea how they have performed within the class.

We provided a report in Moodle that is visible to the student. The report is available for each module and presents the student with each of the grades for the various assignments within a module

screenshot from Moodle report

Figure 1: My “relative grade” report

Figure 1 displays grades for 4 different assignments within a particular module for one student. The figures on the left are the grades achieved, the figures on the right are the relative grade. This relative grade is based on a calculation known as the z score.

A Z-Score is a statistical measurement of a score’s relationship to the mean in a group of scores. A Z-score of 0 means the score is the same as the mean i.e. they are average in the class. A Z-score can also be positive or negative, indicating whether it is above or below the mean and by how many standard deviations. If they achieve the lowest grade they will achieve -3 and if they achieve the highest grade their Z-score will be +3. You will note from the results displayed in figure 1 that this student is consistently below average as their Z-score values are all less than zero. You will also note from that the second assignment has a grade of 56 and a Z-score of -0.99 and the fourth assignment, even though achieving a higher grade (59) was actually a poorer result when compared to his classmates (Z-score of -1.66)

How can the Z-score be useful to staff
As a lecturer you can get an overview of your students’ performance across several assignments through the Z-score
As a student’s tutor or course coordinator you can get an overview as to how a student is doing across several modules as displayed in figure 2 for student John Lennon

a lecturers view of z scores for a student

Figure 2: a Z score displaying a student’ performance across all of their modules

Figure 2: a Z score displaying a student’ performance across all of their modules

Z-Scores to assist with student retention
A potential project in the future will be integration of the Z-score with the student CRM. So if the student has, for example, 2 or more Z-scores in a programme below -1 a flag can be raised to identify that student as a being at risk of non-completion. A simple intervention could be activated by automatically emailing the student from the course coordinator inviting them to a meeting or simply checking in with the student to ensure everything is alright.

Points to note about the z score

If a Z-Score….

Has a value of 0, it is equal to the group mean.
Is positive, it is above the group mean.
Is negative, it is below the group mean.
Is equal to +1, it is 1 Standard Deviation above the mean.
Is equal to +2, it is 2 Standard Deviations above the mean.
Is equal to -1, it is 1 Standard Deviation below the mean
Is equal to -2, it is 2 Standard Deviations below the mean
Z-Scores are not perfect, they are only meant as a visual indicator of a student’s performance

For more information on a z score please refer to:


About Mark Glynn

Head of Teaching Enhancement Unit, Dublin City University

Posted on January 18, 2015, in Uncategorized. Bookmark the permalink. Leave a comment.

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