Day 135 The data from a survey of high school math and science teachers show that in the district of Sanlee many of these teachers reported assigning daily homework
The data from a survey of high school math and science teachers show that in the district of Sanlee many of these teachers reported assigning daily homework, whereas in the district of Marlee, most science and math teachers reported assigning homework no more than two or three days per week. Despite receiving less frequent homework assignments, Marlee students earn better grades overall and are less likely to be required to repeat a year of school than are students in Sanlee. These results call into question the usefulness of frequent homework assignments. Most likely the Marlee students have more time to concentrate on individual assignments than do the Sanlee students who have homework every day. Therefore teachers in our high schools should assign homework no more than twice a week.
Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.
五问：
（1）“The data from a survey of high school math and science teachers show that in the district of Sanlee many of these teachers reported assigning daily homework, whereas in the district of Marlee, most science and math teachers reported assigning homework no more than two or three days per week. Despite receiving less frequent homework assignments, Marlee students earn better grades overall and are less likely to be required to repeat a year of school than are students in Sanlee”是事实， “Therefore teachers in our high schools should assign homework no more than twice a week”是结论，值得反驳吗？另外，这个结论说的是 Sanlee区的高中老师布置作业每周不应超过两次还是全国的老师都不应该这样做？结论的范畴不同会导致我们行文反驳的方式不同，希望同学们注意。
（2）Sanlee和Marlee两个区之间的差异，除了布置作业的频率不同之外，是否可能存在其他方面的差异，例如：老师的教学质量不同，学生的天赋不同，甚至教材难度也不同。在这些特质都不同的情况下，能否将两个地区进行类比？你能回顾一下有效类比的基本要求吗？
（3）原文中使用 grades来评判学习效果是否恰当？两个地区是否采用同样的评分标准？另外，简单地对比平均分会存在哪些可能的统计问题？能否简单地认为平均分 85（但有若干学生不及格）要优于平均分 80（每一个学生都能跟上进度）？
（4）作业更少是否意味着学生会更加专注于个人课后作业（ individual assignment）？学生们是否也有可能在空闲时间玩游戏？
（5）布置作业的频率低就能说明作业量少吗？比如，虽然一周只布置两三次作业，但是每一次的作业量都很大，可能会导致总的作业量比每天都布置作业的总量更多。
