Academic achievement is not improved by homework. Homework is designed to indicate to teachers which of their students know the lessons, and which don’t. Homework is just repetitious paper work.
Math homework is an excellent example of this. The third graders sit in the class, and copy the sums from the board. They work out the sums and then the teacher shows them the right answers and they hand in their papers. Now the teacher hands out copies of sums just like the ones on the board and tell the children this is their homework.
The kids who already understand the sums will just do them quickly and hand in the paper.
The kids who didn’t get it in the first place will spend an inordinate amount of time trying to figure it out. Most likely, their parents will help them, and their understanding will not be all that much better.
The only real academic achievement here is the kids who already got it will prove they got it to the teacher. Though up to one third, possibly more, of the kids did not fully grasp the concept behind the sums, the assistance from the parents may mask this. Even if the teacher is aware these children are falling behind, he or she needs to move on to the next unit. Just as sales people must make their quota, teachers must meet their outcomes. All units must be taught and academic comprehension be damned.
In this all too common scenario, homework does not advance academic achievement.
It is usually not until the high school level that homework begins to resemble work that advances a concept. Of course, by this time the achievers are already ahead of the game, and all the homework in the world is not going to help those who have fallen through the cracks of the educational system.
There are creative teachers who do manage to pull many of these kids back from the precipice of the academic void. These teachers usually employ unusual methods and instead of using homework as a tool of reiteration, use it to advance lessons taught in the classroom. In these instances, the argument could be made that homework improves academic achievement. But they are the exception, and not the rule.
Homework is not culprit here. Academic achievement is measured in grades and test scores. It is difficult to use these measures to assess comprehension. They assess the ability to regurgitate facts and figures. A fifth grade child may be able to recite the multiplication tables up to multiples of ten. But ask that same child to apply that skill to making a 24 square grid and he’ll look at you like you just asked him to write out the formula for motor oil.
Until such time as a more viable, more comprehension-based form of measuring achievement is devised, homework will be a tool for calculating what is already known, not building on what has been learned.