污污草莓视频

Bootstrap in practice

This talk focuses on three practical aspects of resampling: communication, accuracy, and software. I'll introduce the bootstrap聽and permutation tests, and discussed how they may be used to help clients understand statistical results. I'll talk about accuracy -- there are dramatic differences in how accurate different bootstrap methods are. Surprisingly, the most common bootstrap methods are less accurate than classical methods for small samples, and more accurate for larger samples. There are simple variations that dramatically improve the accuracy. Finally, I'll compare two R packages, the the easy-to-use "resample" package, and the more-powerful "boot" package.