When the variable is measured at the nominal level, modes are usually reported. Modes are also useful if several modes exist in a sample or population. Finally, if you must use one of the measures of central tendency to represent all the values in your sample, and if you are concerned with not making errors that are simply defined as being incorrect, there is no better representative measure than the mode. When error is defined as simply being incorrect when you guess a variable's value, you measure your error by simply counting how many times you are incorrect. The Count of Errors page illustrates how selecting the mode as the one value to represent your data minimizes error defined in this manner.
Some textbooks define major and minor modes in a distribution.
However, this distinction is not definitionally correct. The figure on the left, shows a distribution that some statisticians would say has a major and a minor mode. Obviously, there are two distinct humps. However, there is clearly only one score with the most frequencies. Using Statlets to calculate the Mode You can use this Statlets page to quickly calculate the mode for a data set.