Different Outcomes of the Wilcoxon—Mann—Whitney Test from Different Statistics Packages

@article{Bergmann2000DifferentOO,
  title={Different Outcomes of the Wilcoxon—Mann—Whitney Test from Different Statistics Packages},
  author={Reinhard Bergmann and John Ludbrook and Will Spooren},
  journal={The American Statistician},
  year={2000},
  volume={54},
  pages={72 - 77}
}
Abstract The Wilcoxon—Mann—Whitney test enjoys great popularity among scientists comparing two groups of observations, especially when measurements made on a continuous scale are non-normally distributed. Triggered by different results for the procedure from two statistics programs, we compared the outcomes from 11 PC-based statistics packages. The findings were that the delivered p values ranged from significant to nonsignificant at the 5% level, depending on whether a large-sample… 
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