Answers are grounded in this paper and cite their sources.
We consider a fixed‐sample parallel‐group clinical trial with an interim analysis that tests Ho: μx = μy against H1: μx < μy. If we do not reject at the interim analysis, then the probability of making a type I error by rejecting Ho in favour of H2: μx > μy and the power at the final analysis are not appreciably affected by performing the interim analysis for certain relevant critical regions.
No takes yet. Share an insight, caveat, or question.
Chi et al. (1986) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: