前概念,又叫前科学概念,在教学中范指学生在新课教学前,对所学知识已有的认识和了解.学生在学习物理课之前,在其脑海里已经对一些问题形成了他的前概念,有些是正确的,有些是模糊的,有些甚至是错误的.对于《平面镜成像》一课,老师们对于学生错误的前概念关注极少,而这恰恰是学生应用知识解决实际问题的困难所在,本节课前概念的错误主要有三点:物体通过平面镜所成的像在镜子里面;物体离平面镜越远,所成的像越小;“水中的倒影”与“平面镜成的像是正立的”矛盾.通过课例分析,提醒我们教学中要促进学生头脑中的前概念发生转变,使学生在发展科学探究能力的同时更好地学习物理. Pre-concept, also known as the concept of pre-science, refers to the teaching of students in the new lesson before the knowledge and understanding of what they have learned before the students in physics class, in his mind has formed a number of problems for him Some of the preconceptions are correct, some are vague, and some are even wrong.For the class of “flat mirror imaging”, teachers pay little attention to the mistaken preconceptions of the students, and it is precisely for students to apply knowledge to solve practical problems Of the difficulties, the concept of this class before the error of the main three points: the object through the plane mirror into the mirror inside; object farther away from the mirror, the smaller the image; “water reflection ” and "plane mirror Through the case analysis, we remind us that teaching should promote the transformation of the preconceptions in students’ minds so as to enable students to better study physics while developing scientific inquiry ability.