Duncan’s Multiple Range Test

Duncan’s multiple range test, or Duncan’s test, or Duncan’s new multiple range test, provides significance levels for the difference between any pair of means, regardless of whether a significant F resulted from an initial analysis of variance. Duncan’s test differs from the Newman–Keuls test (which slightly preceded it) in that it does not require an initial significant analysis of variance. It is a more powerful (in the statistical sense) alternative to almost all other post hoc methods.

When introducing the test in a 1955 article in the journal Biometrics, David B. Duncan described the procedures for identifying which pairs of means resulting from a group comparison study with more than two groups are significantly different from each other. Some sample mean values taken from the example ...