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Testing whether treatment is ‘better’ than control with ordered categorical data: an evaluation of new methodology
Author(s) -
Cohen Arthur,
Sackrowitz Harold B.,
Sackrowitz Marian
Publication year - 2000
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/1097-0258(20001015)19:19<2699::aid-sim560>3.0.co;2-d
Subject(s) - categorical variable , wilcoxon signed rank test , mann–whitney u test , test (biology) , computer science , statistics , machine learning , mathematics , paleontology , biology
A new test procedure is presented for the problem of testing whether a treatment is better than a control when there is ordered categorical data. The new test is based on the methodology developed for general ‘one‐sided’ alternatives by Cohen and Sackrowitz. An evaluation of the test is made by comparing the power and expected p ‐values of the test with those of the Wilcoxon–Mann–Whitney test in examples. As predicted by the theoretical work by Cohen and Sackrowitz, the new test is seen to be preferable to the Wilcoxon–Mann–Whitney test. Computer programs to assist implementation of the new test are made available. Copyright © 2000 John Wiley & Sons, Ltd.