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Paired t Test

  1. Henry Hsu,
  2. Peter A. Lachenbruch

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15112

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Hsu, H. and Lachenbruch, P. A. 2005. Paired t Test. Encyclopedia of Biostatistics. 6.

Author Information

  1. Food and Drug Administration, Rockville, MD, USA

Publication History

  1. Published Online: 15 JUL 2005


This is used to compare mean differences between treatments when the observations have been obtained in pairs. The difference between the paired values is assumed to be normally distributed, and the null hypothesis that the expectation is zero is tested by Student's t test. The robustness properties are discussed, as is the asymptotic relative efficiency of nonparametric alternatives.


  • student;
  • degrees of freedom;
  • robustness;
  • ARE;
  • nonparametric;
  • distribution-free;
  • signed rank;
  • normal scores