Val- there is other research that refutes the above data too- it's really all over the place. I have read "Rethinking Homework" and also "The Case Against Homework", as well as a bunch of Kohn works. The general data seems to suggest that for middle class, parent involved students, homework has absolutely no affection on retention, standardized test scores or long-term memory until you reach the end of high school years. Homework in math in particular does show a pretty useful jump in the post-Algebra I period.
We're homeschooling this year in large part due to homework. My DS's school's philosophy was that 10 minutes per grade, per night PLUS 30 minutes of logged silent reading was a good idea. In addition, the kids all had long-term projects once a month. In third grade, on a good night, he had an hour of homework, on a bad one- it was more like 2.
All of the homework sheets were repetition of what had been done in class. In addition, the homework was not differentiated (to fill in "Gaps") so he would be doing 6th grade math in class and 3rd grade homework. I finally just gave up and stopped fighting. In a standards based report card system, it doesn't actually matter if you do the homework LOL! So he got a "U" for turns in homework on time and got an E+ "exceeds the standard" in everything else.
