1.Use BoxSampler to generate a sample of size 10 from a Normal Distri
bution }}ith mean 0.5 and variance 1.
第一步:使用箱式取样器产生一个来自于正态分布均值为0.5,方差为1的大小为10的一个样本
2 Use this sample and the t-test to test the hypothesis that the mean of
the population from }}hich this sample }}as dragon }}as 0 (not 0.5).
Write do}}n the value of the t statistic and of they value.
第二步:利用这个样本和t检验去检验抽取的这个样本来自的总体的均值是0(而不是0.5),记录下t统计量和p值
3 Repeat Step 1.
第三步:重复第一步
4 Repeat Step 2.
第四步:重复第二步
The composition of the two samples varies, the value of the t statistic
varies, the p values vary, and the boundaries of the confidence interval
vary. What remains unchanged is the sight访‘。二。level of 100%一95%=50/
that is used to make decisions.
两个样本的构成改变了,t统计量的值也改变了,p值也改变了,置信区间的边界也改变了。仍然保持不变的是用于做决策的显著性水平(100%-95%=5%)
You aren't confined to a 5% significance level. In clinical trials of drug
effectiveness, one might use a significance level of 10% in pilot studies but
would probably insist on a significance level of 1% before investing large
amounts of money in further development.
你们不能狭隘的理解5%这个显著性水平。在临床尝试药效(诊断)时,在试点研究中人们可能使用10%的显著性水平,而在未来发展中要进行大量资金投资时大概要坚持1%的显著性水平
In summary, p values vary from sample to sample, whereas significance
levels are fixed.
总之,p值是随着样本的变化而变化,而显著性水平却是固定。
Significance levels establish limits on the overall frequency of Type I
errors.
显著性水平是建立在全体范围中第一类错误频繁发生基础上The significance levels and confidence bounds of parametric and
permutation tests are exact only if all the assumptions that underlie these
tests are satisfied. 显著水平、参数的置信区间边界以及置换检验只有在所有假设在这些检验都满足的条件下是确切的Even when the assumptions that underlie the bootstrap are satisfied, the claimed significance levels and confidence bounds of the
bootstrap are only approximations. The greater the number of observa-dons in the original sample, the better this approximation will be.
即使当这些假设在解靴带(辅助程序)是感到满意的,我们断言显著性水平和解靴带条件下置信区间(边界)只是一种近似。在原始样本基础上,研究者——大学教师的数量越多,这种近似将会越好。