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ERIC Number: EJ818903
Record Type: Journal
Publication Date: 2008
Pages: 18
Abstractor: As Provided
ISSN: ISSN-0022-0973
Sample Size Determination for One- and Two-Sample Trimmed Mean Tests
Luh, Wei-Ming; Olejnik, Stephen; Guo, Jiin-Huarng
Journal of Experimental Education, v77 n2 p167-184 Win 2008
Formulas to determine the necessary sample sizes for parametric tests of group comparisons are available from several sources and appropriate when population distributions are normal. However, in the context of nonnormal population distributions, researchers recommend Yuen's trimmed mean test, but formulas to determine sample sizes have not been developed. The authors address this omission and provide statistically rigorous formulas of sample size determination for 1- and 2-sample Yuen's trimmed mean tests. Computer simulations for a wide range of nonnormal distribution shapes evaluated the adequacy of the proposed formulas. The results show that the proposed formulas control Type I error satisfactorily and achieve desired power, whereas the traditional formulas resulted in oversampling units for nonnormal distributions. (Contains 5 tables.)
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Publication Type: Journal Articles; Reports - Research
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A