# Definition of terms

A list of standard terms we use in our reporting on Course Enhancement Questionnaires.

**Mean average:**

The **mean** is the average of the numbers. It is found by adding up the results for each question, then dividing by the number of respondents. The practice of taking the mean of ordinal data like this has limitations, but is a rough guide to result.

**Median score:**

The **median** is the middle value in the list of numbers. It is found by:

• Putting all the numbers selected from the scale in numerical order.

• If there is an odd number of results, the median is the middle number.

• If there is an even number of results, the median will be the mean of the two central numbers.

**Standard deviation:**

A normal distribution of data means that most of the examples in a set of data are close to the average, while relatively few examples tend to one extreme or the other.

The **standard deviation** can tell you how spread out the examples in a set are from the mean and can help find the story behind the data.

**Confidence interval:**

A confidence interval is a range of values that describes the uncertainty surrounding an estimate. In this case the estimate would be the mean average. A confidence interval is also itself an estimate. It is made using a model of how sampling, interviewing, measuring, and modelling contribute to uncertainty about the relation between the true value of the quantity we are estimating and our estimate of that value.

Due to the sample size on many courses, small differences between values are not likely to be statistically meaningful. Statistical differences between the ratings could use the standard deviation to calculate confidence intervals.