Current sample size conventions: flaws, harms, and alternatives.

ABSTRACT:

Background

The belief remains widespread that medical research studies must have statistical power of at least 80% in order to be scientifically sound, and peer reviewers often question whether power is high enough.

Discussion

This requirement and the methods for meeting it have severe flaws. Notably, the true nature of how sample size influences a study's projected scientific or practical value precludes any meaningful blanket designation of <80% power as "inadequate". In addition, standard calculations are inherently unreliable, and focusing only on power neglects a completed study's most important results: estimates and confidence intervals. Current conventions harm the research process in many ways: promoting misinterpretation of completed studies, eroding scientific int

SUBMITTER: Bacchetti P 

PROVIDER: S-EPMC2856520 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature