Newman-Keuls Test

An outdated and faulty test to compare multiple groups

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Newman-Keuls (NK) Test is a proposed statistical analysis for pairwise comparisons among a set of treatment means, which has since become outdated¹.

Issues

Does not account for Family-wise error rate

A problem with Newman-Keuls Test and the reason it does not have contemporary use is the fact that it does not account for “family-wise error rate (FWER)” at the nominal level¹. Resulting in possibly inflated Type 1 error rate¹

Confidence Intervals

Newman-Keuls Tests cannot compute CIs²

References

1.

Shaffer JP. Controlling the false discovery rate with constraints: The Newman-Keuls test revisited. Biometrical Journal Biometrische Zeitschrift. 2007;49(1):136-143. doi:10.1002/bimj.200610297

2.

Motulsky H. Intuitive Biostatistics: A Nonmathematical Guide to Statistical Thinking. 4th ed. Oxford University Press; 2018.