The median is the value below which half the data or probability distribution lies - when the sample size is odd, the median is the 'middle' value of an ordered sample.
The median is the value above which, and below which, half the data lies. If the number of data is odd, the median is the middle value when the sample is ordered; if the number of data is even, the median is the mean of the two middle values when the sample is ordered.
- The median can be considered an appropriate measure of central tendency for an ordinal level variable.
- It is often considered a more representative measure than the mean, even for interval data, when the distribution is highly skewed.
- Medians are more robust (but less efficient) measure when the data may be contaminated.