Comparative performance of pseudo-median procedure, Welch’s test and Mann-Whitney-Wilcoxon at specific pairing
The objective of this study is to investigate the performance of two-sample pseudo-median based procedure in testing differences between groups.The procedure is the modification of one-sample Wilcoxon procedure using pseudo-median of differences between group values as the central measure of locat...
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Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Canadian Center of Science and Education
2011
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Subjects: | |
Online Access: | http://repo.uum.edu.my/7431/1/F7.pdf http://repo.uum.edu.my/7431/ http://dx.doi.org/10.5539/mas.v5n5p131 |
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Institution: | Universiti Utara Malaysia |
Language: | English |
Summary: | The objective of this study is to investigate the performance of two-sample pseudo-median based procedure in
testing differences between groups.The procedure is the modification of one-sample Wilcoxon procedure using
pseudo-median of differences between group values as the central measure of location.The test was conducted
on two groups setting with moderate sample sizes of symmetric and asymmetric distributions.The performance
of the procedure was measured and evaluated in terms of Type I error and power rates obtained via Monte Carlo
methods.Type I error and power rates of the procedure were then compared with the alternative parametric and
nonparametric procedures namely the Welch's test and Mann-Whitney-Wilcoxon test.The findings revealed that
the pseudo-median procedure is eapable in controlling its Type I error close to the nominal level when heterogeneity of variances exists.In terms of robustness, the pseudo-median procedure outperforms the Welch's and Mann Whitney Wilcoxon tests when distributions are skewed.The pseudo-median procedure is also capable in maintaining high power rates especially for negative pairing. |
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