There was a vivid bit of memory, which I can't say that it's a pleasant one, but rather, an educational one. The bit takes me back to a certain event when I was seven (second grade, I believe). It was rather morning (I guess 5:30, since the class would start at 7), I was re-reciting several verses from the Bible since some of the parts would be asked during written test. No kidding. So, there I was, with my mom, checking the verses in the Bible while I re-recited them. I wasn't very sure what was the purpose of the test, but when adults said "It must be done,"; then so be it.
Why suddenly the bit pops out, I have no idea. There is but one verse that I remember until now (Romans 6:23). As for the rest, I think my brain rearrange the priority slots. But you may ask why Romans 6:23? Here it is: "For the wages of sin is death, but the gift of God is eternal life in[a] Christ Jesus our Lord." I don't know why, but somehow, I think there's a link between that verse, and the "reward-punishment" method that my parent used.
You see, for me, the "reward-punishment" method is something similar to the "treat" training, if you own a pet. For me, while the punishment could come in the form of caning (rattan), the reward itself might come in the form of either toys, comic books, or movie tickets. Less than 60 points means rattan, while 100 points means a reward. How about 60-99? Well, depends on the situation, but I was hoping that rattan would not swing.
So, was the method useful? I would say, yes-and-no. Academically speaking, in my own opinion, the method is pretty much useful, as long as I could upgrade myself to enter the next class. Whether I could grasp the core or not, it didn't matter. Before I entered university, although I chose to enter science class, the highest mark was on the English test. On several events in my life, it does help me, like, a lot. While for the others, well, there's a wikipedia to check on - for example - what medulla oblongata can do. Or wolfram-alpha to check what's the relationship between sin and cos. Please don't ask "Why medulla oblongata?" and say that relationship between sin and cos is pretty much okay and they meet at 45.
In the end, until now, when it comes to the working stuffs, that method still exists in several fields, no matter what. No one will complain as long as the excitements and rewards (simply say salary) are there. But there's one thing: I can't answer whether it's useful or not. Imagine a zocchihedron. That's my best answer, up to now.