A Study On The Concept Of "Ecological System" In Senior High School And Practical Research On Teaching Optimization Strategy

A large number of scientific research and biology teaching practice show that people construct new knowledge and understand new knowledge on the basis of the existing knowledge. Learning is not a simple information accumulation, but a process of restructuring existing knowledge from experience and the new knowledge we learn. In the teaching practice, the knowledge that students have already known exists spontaneously in their brain, which will impact their learning of new concept. Therefore, in order to reduce the blindness and ineffectiveness of teaching and promote the secondary school biology class teaching, teachers need to use a variety of methods to gain and change the students’pre-conceptions more accurately and promptly.Combining domestic and foreign relevant researches, I devoted to researching on the pre-conceptions of compulsory text book3(PEP), chapter5the ecological system and its stability and the practice of its transformation.First, I collected related articles on pre-conceptions and conceptual change, analyzed current situation, and put forward my own understanding of pre-conceptions. Then, I elaborated the research mentality and the method, interviewed some biology teachers for their opinion of pre-conceptions and how to get them, and searched for the related pre-conceptions of ten important conceptions in this chapter by questionnaire investigation method (Two-tier diagnostic test). I researched on many different pre-conceptions of a concept, and confirmed the major pre-conceptions according to the statistics on the percentage of them. Research shows that the pre-conceptions in students’brain are very rich, which plays an important role in the formation of the scientific concept. Also, study on the difference between students from grade one and grade two shows that the reasons of the formation of the pre-conceptions come from students’experience of daily life, previous learning, cognitive ability, the one-sided understanding of the conceptions and so on. Next, I optimize some existing teaching strategies, put forward a pre-conception changing strategy using students as the main body according to the concept of "NN three steps change modes". During the teaching process of "the ecological system structure", I implemented different teaching process in the routine class and experimental class, and had students pretested and protested before and after teaching respectively, and evaluated the effect of the conceptual change. The results show that using this mode to teach is better than the normal mode. At last, I suggest that the biology teacher update their educational conception, fully understand the pre-conceptions of objectivity existence, pay attention to the system research of getting students’ pre-conceptions, and make full use of pre-conceptions before conceptual change in the teaching design.