Examination is a tool testing knowledge and skill. People especially parents think much of the results of the examination. What will they do if their kids did not get a satisfying result? Criticize their kids or to blame the teachers? In my point of view, the parents should analyze the reason of why their kids didn’t perform well first.
One probable reason is that the kids don't study hard. It is impossible for a lazy student to get a high score in an examination. Many successful men express the familiar idea that success is made of 1/10 inspiration and 9/10 sweat. Therefore, the parents should try to persuade and encourage their kids to study hard.
If the examination is very difficult for most of the students, it is natural for the kids to get a low score. One case is that the teacher did not realize how the students are and consider a harder exam as an easy one. Another case is that the teacher intentionally makes a difficult examination, because he wants the students not to feel self-satisfied, and realize that they still have puzzles then they will study harder. Neither an easy examination nor a difficult one is appropriate to test the students because they will make the students feel either self-satisfied or frustrated and it will be difficult to differentiate the levels of the students. Therefore, the best average of an examination, I think, should be 75.
The unqualified teacher also can result in the bad score. If they can't teach clearly and always confuse the students, even the simple problem will be difficult to understand and the students will also lose the interest in study. In this case, it is necessary to communicate between the teacher and the parents.
Anyway, when the kids have a bad score in an examination, parents should analyze the reason, and then take a right measure.
