Spread | Statistics

Spread concerns how values differ from the central value in a data set. The spread is measured in data, since measurements of scattering gives important information about how the data is distributed.

A mean value indicates the average value in a data set. A small variance in a data set means that the values are around the mean and that the mean is a good representative of the data set, the mean is reliable. A large spread in a data set means that values are far from the mean and that the mean is a poor representative of the data set, the mean is not reliable.

Measurements of spread can also be used to compare several different distributions or datasets and to assess the reliability of mean values. Spread can be measured with variation width, average deviation, standard deviation and variance.