The διάμεσο (Median) is a statistical measure that represents the middle value of a data set when it is arranged in ascending or descending order. If the data set has an odd number of values, the median is the middle number. If it has an even number of values, the median is calculated by taking the average of the two middle numbers. The median is useful because it provides a measure of central tendency that is less affected by extreme values, or outliers, compared to the μέσος όρος (mean). This makes it a reliable indicator of the typical value in a data set.