don't agree with this contend that if children want to do well in school, parents should limit the hours of watching TV programs or movies, because I think most TV programs and movies have nothing to do with how a child can perform in school, moreover, some TV programs or movies may motivate children's enthusiasm in learning and help them do well in school.
Firstly, TV programs have no direct relations with children's performance in school. Take my brother for example, when he was 12 years old, he always ranked 1st in his class, and to most people's surprise, he is also fond of watching TV programs especially some episodes like Big Bang Theory. After watching these programs, he aspired to be a scientist, and tried his best in science subjects. So even some positive factors existed when my brother watched TV programs.
Secondly, in modern society, media tides actually cannot be avoided. If parents forbid childrens watching TV at home, they also have other access to these medias through Internet or other things. Without any control from parents, children may get access to some bad TV programs filled with violence or pornography easily. So limit the hours of watching TV may result in many other problems in chileren's grow up.
Last but not least, although I understand many people think that watching to many TV programs is a waste of time, it also is considered as a easy way to recreate children's minds and make them relaxed after a whole day's hard work. In China, parents often limit chileren's hours of watching TV programs strictly. Children cannot feel warm in their families because of heary burden of homework and strict regulations. I think children cannot benefit from this psycological condition and cannot do well in school.
In conclusion, I don't agree with limiting children's hours of watching TV in order to help them do well in school. To help them do well in school, the most important thing is to help them build up confidences and interests. Moreover, Learning is process of gaining experiences in people's lives and we have no reason to toss up a part of our lives.