建构主义认为,学习是学习者以其已有的知识和经验为基础的主动建构,学生能否理解学习内容,主要取决于主体能否在新的学习内容与其已有的知识和经验之间建立适当的联系。因此,选择恰当的学习素材,创设一个适合教学和学生发展需要的情境,已成了广大教师的共识。但是,在初中化学教学中,有些教师往往花很大的时间和精力去创设情境,而辛辛苦苦创设的情境却没有起到应有的作用,这究竟是为什么呢?笔者认为,教学 Constructivism holds that learning is the active construction of learners based on their existing knowledge and experience. Whether students can understand the learning content depends mainly on whether the subject can be established between the new learning content and its existing knowledge and experience Appropriate contact. Therefore, the choice of appropriate learning materials to create a suitable teaching and student development needs of the situation has become the consensus of the majority of teachers. However, in junior high school chemistry teaching, some teachers tend to spend a great deal of time and energy to create situations, while the hard-working situations have not played their due role. What is the reason? In my opinion, teaching