The coefficient of variation is the coefficient between the standard deviation and mean of a data set. Like variance, the coefficient of variation is a measure of how densely packed a dataset is. A small coefficient of variation points to a data set that does not vary very much from the mean. A large coefficient of variation indicates a data set that is spread out, with many pieces of data far from the mean. Along with other measures like standard deviation and variance, the coefficient of variation helps to give viewers an understanding of how the data is distributed relative to the mean.