课堂教学中教师对学生科学、恰当、正确的评价是师生情感和思想交流的重要手段,评价运用的正确得当与否,能调动起宽松和谐的课堂氛围,直接影响着课堂的教学效果,对顺利高效完成课堂教学目标、教学任务和培养学生的正确的情感态度和价值观作用非同小觑。当前,部分学生学习主观能动性不强,学习动机薄弱,往往是被动学习居多。要激发学生积极正确的学习动机,教师在课堂中引入恰当及时的评价非常重要。 Classroom teachers in science, proper and correct assessment of teachers and students is an important means of emotional and ideological exchanges, evaluation of the proper use of appropriate or not, can mobilize a relaxed and harmonious atmosphere in the classroom, a direct impact on classroom teaching effectiveness, right Smooth and efficient completion of classroom teaching objectives, teaching tasks and develop students’ correct emotional attitude and values ​​play a role. At present, some students study subjective initiative is not strong, learning motivation is weak, often passive learning. To motivate students to actively motivate correct learning motivation, it is important that teachers introduce appropriate and timely evaluations in the classroom.