In:
Evaluation & the Health Professions, SAGE Publications, Vol. 26, No. 3 ( 2003-09), p. 258-287
Abstract:
Sample-size planning historically has been approached from a power analytic perspective in order to have some reasonable probability of correctly rejecting the null hypothesis. Another approach that is not as well-known is one that emphasizes accuracy in parameter estimation (AIPE). From the AIPE perspective, sample size is chosen such that the expected width of a confidence interval will be sufficiently narrow. The rationales of both approaches are delineated and two procedures are given for estimating the sample size from the AIPE perspective for a two-group mean comparison. One method yields the required sample size, such that the expected width of the computed confidence interval will be the value specified. A modification allows for a defined degree of probabilistic assurance that the width of the computed confidence interval will be no larger than specified. The authors emphasize that the correct conceptualization of sample-size planning depends on the research questions and particular goals of the study.
Type of Medium:
Online Resource
ISSN:
0163-2787
,
1552-3918
DOI:
10.1177/0163278703255242
Language:
English
Publisher:
SAGE Publications
Publication Date:
2003
detail.hit.zdb_id:
2067657-8
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