Since the 20th century , the pace of development of science and technology faster. In teaching also developed quite rapidly. In the 19th century , when the students in the classroom, school, or come into the front row of neat chalkboard blackboard . Today makes the development of multimedia teaching has also changed , the student is no longer facing a blackboard lifeless , but a colorful world . Multimedia teaching the textbook move , I thought this can arouse students ' interest , the result is just the opposite , became an embroidered pillow , impractical , the student's attention was attracted by bright colors , forget listening to the teacher . The classroom should have knowledge of multimedia altogether because some teachers are no longer writing on the blackboard , a class down , lectures who feast for the eyes , in addition to the blackboard blackboard topics no other traces. In fact , the screen can not replace the necessary writing on the blackboard . Oxford University published " education ", said: "All the visual aids , to the number of the board 's most common, most important, perhaps because the board is too flexible and familiar to people , so often overlooked or underutilized . "