在前一章,我们初步了解了假设检验的基本步骤与两类错误。在本章,我们继续学习z检验的相关知识,并且区分了效力和效应,了解提高效力的途径。与z检验相比,t检验大多是在方差未知的情况下进行的,我们以样本方差代替标准差,结合对应的自由度进行假设检验。
In the previous chapter, we preliminary understanded the basic steps and two types of errors of hypothesis testing. In this chapter, we continue to learn about the relevant knowledge of Z-tests and distinguish between efficacy and effect, understanding ways to improve efficacy. Compared with the Z-test, T-test is mostly conducted when the variance is unknown. We use sample variance instead of standard deviation and combine it with corresponding degrees of freedom for hypothesis testing.