APPENDIX 3: EXPLANATION OF UNIT STATISTICS
It is recommended that this document is distributed to all Board Members to provide an explanation of the statistics displayed in the Unit Details report. This document should assist in alleviating uncertainties about the information that is being presented to them.
The graphical representation you will see is a Box Plot. It looks something like this
This end of the thick black line represents the minimum value.
The lowest percentage that occurs out of all percentages achieved
This end of the thick black line represents the maximum value.
The highest percentage that occurs out of all percentages achieved
The vertical line inside the box represents the median value.
The value which cuts off the lower and upper
50% of all percentages achieved.
This end of the box represents the upper quartile value.
The value which cuts off the highest 25% of all percentages achieved
This end of the box represents the lower quartile value.
The value which cuts off the lowest 25% of all percentages achieved
There will be an illustration, like the one above, for each unit. The box plot at the bottom of the page will be for the unit total and represent all students on the unit. Box plots representing the unit performance for each of the programmes/pathways are shown above the (framework) unit total.

Total Students Assessed
This figure is displayed on the two unit statistics reports (2 and 3); it is the total number of students who have been assessed in each element and unit. If a student withdrew or suspended prior to completing the assessment for the unit then they are excluded from this figure and they do not contribute to the other statistics.
NOTE: If a student has postponed an exam (PP), had an extension on a piece of work (EXT), have not yet been assessed in an element (NYA) or if their mark is not known (MNK) then they are not considered to be assessed. They have been removed from the Total Students Assessed figure and they do not contribute to the other statistics.
Mean
This is derived by the sum of all the student percentages, divided by the total number of students that have been assessed.
Median
This is the value which cuts off the lower and upper 50% of all percentages achieved. It is exactly in the middle of all percentages achieved.
Mode
This is the percentage that occurs most frequently in the whole set of student percentages.
NOTE: If there is no mode i.e. every percentage occurs just once or if there is more than one percentage that occurs the same number of times then the Minimum value is displayed instead.
Standard Deviation
This shows the amount of variation from the mean. A low standard deviation indicates that the majority of percentages tend to be very close to the mean (illustrated by a short box), a high standard deviation indicates that the percentages are spread out over a large range of percentages (illustrated by a long box).
Zero Marks
If a student is genuinely awarded a mark of zero (this is very rare but if it does occur then it will be represented with a code that says ZERO) then this zero mark will be included in the unit statistics. If a student is awarded a mark of zero due to NS (Non Submission), LS (Late Submission) or AOD
(Academic Offence Decision) then this zero mark will be excluded from the unit statistics.
Repeating Capped
When a student is repeating a unit and their mark has been capped, the original uncapped mark will be included in the statistics.