PsychStatsWiki

ANOVA无法说明哪个备择假设得到支持；
- The ANOVA cannot indicate which alternative hypothesis is supported.
要进行事后检验以说明各组差异在什么地方；
- Post-hoc tests are needed to show where the groups differ.
事后检验是比较每一个组和另一个处理组，一次比较两个，这称为成对比较。
- Post-hoc test compares each group to another treatment group, two at a time; this is called a pairwise comparison.

每一个比较都是一个单独的假设检验，每一个都有犯I类错误的风险。所以，比较对数越多，作结论的风险越大。即容易发现实际不存在的差异。这称为实验导致的（experimentwise）alpha水平或族系（familywise）误差；
- Each comparison is a separate hypothesis test, each with the risk of making a Type I error. So the more pairs of comparisons there are, the greater the risk of making a conclusion. That is, it is easy to find differences that do not actually exist. This is called the experimentwise alpha level or familywise error.
多次比较后犯I类错误的概率(Probability of making a Type I error after multiple comparisons)为α_EW=1-(1-α）^c，其中c为比较的次数(c=Number of comparisons)。

此检验各组要有相同的样本容量;
- This test requires the same sample size for each group.
可以计算出单一的值确定处理均值间的最小差异，考查此差异在统计上是否显著;
- A single value can be calculated to determine the smallest difference between treatment means, to see if the difference is statistically significant.
q可以查表得到。
- q score can be obtained by looking up the table.

适用于n不相等的情况;
- Applies when n is not equal.
降低I类错误的风险，提高II类错误的风险。
- Reduces the risk of Type I errors and increases the risk of Type II errors.