R中的两种Anova检验方法的差异

Question

你好，这两种方法在R-两种方式的Anova测试中有什么区别：

1. anova(lm(StressReduction~Treatment*Gender))
2. anova(lm(StressReduction~Treatment+Gender))

如你所见，第一个是“治疗*性别”，最后一个是"Treatment+Gender“。

我应该用哪一种？

  Treatment Gender StressReduction
1    medical      F               1
2    medical      F               1
3    medical      F               1
4    medical      F               1
5    medical      F               2
6    medical      F               2
7    medical      F               3
8    medical      F               3
9    medical      F               3
10   medical      F               3
11   medical      M               1
12   medical      M               1
13   medical      M               2
14   medical      M               2
15   medical      M               2
16   medical      M               2
17   medical      M               2
18   medical      M               2
19   medical      M               3
20   medical      M               3
21    mental      F               3
22    mental      F               3
23    mental      F               4
24    mental      F               4
25    mental      F               4
26    mental      F               4
27    mental      F               4
28    mental      F               4
29    mental      F               5
30    mental      F               5
31    mental      M               2
32    mental      M               2
33    mental      M               2
34    mental      M               2
35    mental      M               3
36    mental      M               3
37    mental      M               4
38    mental      M               4
39    mental      M               4
40    mental      M               4
41  physical      F               1
42  physical      F               1
43  physical      F               1
44  physical      F               1
45  physical      F               2
46  physical      F               2
47  physical      F               3
48  physical      F               3
49  physical      F               3
50  physical      F               3
51  physical      M               3
52  physical      M               3
53  physical      M               4
54  physical      M               4
55  physical      M               4
56  physical      M               4
57  physical      M               4
58  physical      M               4
59  physical      M               5
60  physical      M               5

Answer 1

这是一个统计问题。这里有很好的幻灯片来解释基本知识。

+符号表示包含其他解释变量。在复杂关系中，我们可能需要在模型中包含“y ~ x1 + x2 + x3交互术语”作为变量。y ~ A * B