As with all quantiles, a decile is a rank-order statistic. A decile divides a distribution of data into 10 equally sized groups determined after ranking the data according to some measure or combination of measures. After offering two meanings for the term decile, this entry provides an explanation of how decile values can be utilized in educational settings, including an example of its use in New Zealand.

The most common quantiles are percentiles, quartiles, deciles, and sometimes quintiles. Percentiles offer too many groups to visualize and to make sense of each group, but deciles provide a fairly large number of groups that can still be treated at one time while still allowing the analyst to deal with each of them as separate entities.

The term decile can ...