SS1
displays the sum of squares associated with Type I estimable functions for each effect. These are also displayed by default.

SS2
displays the sum of squares associated with Type II estimable functions for each effect.

SS3
displays the sum of squares associated with Type III estimable functions for each effect. These are also displayed by default.

SS4
displays the sum of squares associated with Type IV estimable functions for each effect.

这里有个不错的带例子的解释，太长了，自己去看看吧
http://www.ats.ucla.edu/stat/sas/output/sas_glm_output.htm

这是啥子问题吗？ 好高深

谢谢解答 并且这个网站也很实用 http://www.ats.ucla.edu/stat/sas/

那个网站不错，有很多东西可以学习。