11.1 方差分析表概念
回归平方和:SSR(Sum of Squares for regression) = ESS (explained sum of squares)
残差平方和:SSE(Sum of Squares for Error) = RSS (residual sum of squares)
总离差平方和:SST(Sum of Squares for total) = TSS(total sum of squares)
SSE+SSR=SST RSS+ESS=TSS
(决定系数 Coefficient of Determination):
越接近于1,解释力度越大
SEE(Standard Error of Estimate):
Actual Y – Estimated Y
而此时,
为一个垃圾桶,均值为0。
11.2 检验
11.2.1 T检验
(1)点估计(point estimation)
(2)置信区间(Confident Interval)
如果增大,SEE相应上升,因为本质上SEE是描述数据的波动性(variability of data)
检验方法:假设检验
(1)
(2)
(3)画图判断
(4)结论:b1 is significantly different from 0
(5)不一定要与0进行判断
11.2.2 F-检验(联合检验)
(1)
至少有一个
(2)