# Eval25 Calculations

Use these definitions to learn how means and medians are calculated in Eval25.

### Course Mean

The sum of all answers for a question in a course or department is divided by the total number of answers for that question in a course.

### University Mean

This is the mean for all evaluations that included the question specified.

### Course/Department Median

If the center_median option has been turned off or on in a school's Institution Settings, the median is the result that lies in the middle of responses. Half of the responses lie above or equal to the median and the other half lie below or equal.

When center_median is turned on, then a center median is calculated as an interpolated median. The result will be close to a normal median, but will be pulled slightly upward or downward depending on whether there are more responses strictly greater or strictly less than the median.

If a data set is 1, 3, 3, 3, 4, and 5, then the normal median is 3, but since there is only one response strictly below, while two responses are above, the center median will be slightly above 3, or in this case 3 and 1/6th. This median will be rounded to 3.2, per CollegeNET's system.

The exact formula used is:

`normal median + (number of responses above - number of responses below) ÷ (2 x number of responses equal) `

The answer is then rounded to the nearest tenth. The center median is never more than 0.5 in either direction of the normal median.