Document Detail


Optimal sample sizes for Welch's test under various allocation and cost considerations.
MedLine Citation:
PMID:  21512873     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
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.
Authors:
Show-Li Jan; Gwowen Shieh
Related Documents :
21241473 - Is computer aided detection (cad) cost effective in screening mammography? a model base...
17890653 - Topical, residual and ovicidal contact toxicity of three reduced-risk insecticides agai...
21789943 - Managing the risks of accountable care.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-4-22
Journal Detail:
Title:  Behavior research methods     Volume:  -     ISSN:  1554-3528     ISO Abbreviation:  -     Publication Date:  2011 Apr 
Date Detail:
Created Date:  2011-4-22     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101244316     Medline TA:  Behav Res Methods     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Department of Applied Mathematics, Chung Yuan Christian University, Chungli, Taiwan, 32023, Republic of China, sljan@math.cycu.edu.tw.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Generating nonsymbolic number stimuli.
Next Document:  Robustness of parameter and standard error estimates against ignoring a contextual effect of a subje...