The value of a feature that divides the ordered statistical population into two equal parts so that there is an equal number of observations below and above this value. Median is the second quartile. It is worth emphasizing that the median as a positional measure is insensitive to untypical (outlier, extreme) distribution values, its value does not depend on the marginal values of the distribution of the analyzed feature.

• Measures of asymmetry
• Measures of central tendency
• Quartile deviation
• Symmetric series
• Quartile skewness coefficient
• Coefficient of variation of the quartile deviation

• Structural point series
• Series of distribution with class intervals
• Detailed series
• Arithmetic mean