Comparison of sample size reestimation procedures: Bias versus variance in variance estimation

Tim Friede & Meinhard Kieser
Kieser and Friede [ref:2] proposed the use of the total variance estimator as an estimator for the within group variance to estimate the sample size in a blinded fashion from data of an internal pilot study [ref:5]. The total variance estimator or one-sample variance is an appropriate[for full text, please go to the a.m. URL]