標題: Optimal sample sizes for Welch's test under various allocation and cost considerations
作者: Jan, Show-Li
Shieh, Gwowen
管理科學系
Department of Management Science
關鍵字: Behrens-Fisher problem;Power;Study design
公開日期: 1-十二月-2011
摘要: The issue of the sample size necessary to ensure adequate statistical power has been the focus of considerableattention in scientific research. Conventional presentations of sample size determination do not consider budgetary and participant allocation scheme constraints, although there is some discussion in the literature. The introduction of additional allocation and cost concerns complicates study design, although the resulting procedure permits a practical treatment of sample size planning. This article presents exact techniques for optimizing sample size determinations in the context of Welch (Biometrika, 29, 350-362, 1938) test of the difference between two means under various design and cost considerations. The allocation schemes include cases in which (1) the ratio of group sizes is given and (2) one sample size is specified. The cost implications suggest optimally assigning subjects (1) to attain maximum power performance for a fixed cost and (2) to meet adesignated power level for the least cost. The proposed methods provide useful alternatives to the conventional procedures and can be readily implemented with the developed R and SAS programs that are available as supplemental materials from brm.psychonomic-journals.org/content/supplemental.
URI: http://dx.doi.org/10.3758/s13428-011-0095-7
http://hdl.handle.net/11536/14970
ISSN: 1554-351X
DOI: 10.3758/s13428-011-0095-7
期刊: BEHAVIOR RESEARCH METHODS
Volume: 43
Issue: 4
起始頁: 1014
結束頁: 1022
顯示於類別:期刊論文


文件中的檔案:

  1. 000297169200013.pdf