置信区间和显著性水平的区别

问题如下：

Which of the following outcomes would most likely occur with a decrease in the confidence level?

选项：

A.

Increased probability of making a Type I error.

B.

Decreased probability of making a Type I error.

C.

Increased probability of making a Type II error.

D.

Decreased probability of making a Type II error.

解释：

A is correct.

考点：Type one error & Type two error

解析：减小confidence level也就是增加significance level，比如99%的confidence level 减小到95%，这会减少接受域的面积，增加拒绝域的面积，也就是更容易拒绝原假设，更容易犯第一类错误。