No, Not because they are sadists! 🙂
Teachers know that lack of homework causes the Ebbinghaus Forgetting Curve to kick in with a vicious vengeance. Herman Ebbinghaus, the German psychologist who took up intensive studies on memory retention abilities of the human brain. He experimented on himself and plotted his findings into what is today famously referred as the ‘Forgetting Curve’
Any new stuff learnt is 100% retained only during the instant that it is learnt. Following that the newly learnt details start leaking out rapidly. So much so that 20 minutes later you can effectively recall only 58% of the original details. At the end of 24 hours, you have lost an amazing 66%.
Now imagine the situation that teachers do not give homework. Children will come to the class with their memories wiped nearly clean of what has been freshly learnt at class.
The only workaround for this is to repeat, repeat and repeat the learning. Every successive repetition commits larger chunks of new information to Long Term Memory.
This is also the reason that teachers spend about 10 -15 minutes of every period recalling what was discussed in the previous class.
