本章概览 (Guide)：

• 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.

学习要点 (Learning Points)：

1. 区分单尾检验与双尾检验
   Distinguishing between single tailed and two tailed tests
2. 掌握z检验的步骤与前提
   Master the steps and prerequisites of z-test
3. 学习什么是效力、怎样提高效力
   Learn what power is and how to improve it
4. 学会计算和评价处理效应
   Learn to calculate and evaluate processing effect
5. 掌握t统计量和t检验的步骤
   Mastering the steps of t-statistics and t-test

目录

• 单尾检验与双尾检验 (Single tailed test and two tailed test)
• Z检验的前提 (The premise of Z-test)
• 效力 (Power)
• 提高效力的途径 (Ways to improve power)
• 效应值 (Effect Size)
• t检验 (T-test)

作业

• 2023作业 (homework of 2023)
• 2024作业 (homework of 2024)