A Research On High School Physics Teachers’ Cognition Of Students’ Pre-concepts In Mechanics

Concept teaching is one of the important parts of physics teaching.In order to effectively carry out concept teaching,teachers should understand the students’ existing cognitive foundation,including students’ pre-concepts,and should also master the strategies and methods for diagnosing students’ pre-concepts and transforming pre-concepts into scientific concepts.Therefore,this research aims to investigate high school physics teachers’ cognition of students’ pre-concepts,help teachers understand students’ pre-concepts in mechanics and transformation strategies,and provide relevant suggestions for teachers’ professional development.Through literature sorting,it summarizes the pre-concepts that students may have in the chapters of gravity,elasticity,friction,and Newton’s law of motion in the field of mechanics.For example: heavy objects fall faster,elasticity is proportional to mass,and static objects can only be affected by Static friction and moving objects must be affected by force,the greater the force,the faster the speed,and the force is generated before the reaction force.Two types of transformation strategies are also summarized: cognitive conflict strategy and knowledge expansion strategy.Among them,cognitive conflict strategies include specific strategies for creating life situations,constructing physical models,teacher demonstration experiments,and students’ exploration experiments.Knowledge expansion strategies include bridging analogies and comparison strategies.Through text analysis of online lesson examples and interviews with offline teachers,it can be found that teachers’ understanding of the pre-concepts of students in mechanics is not comprehensive enough.Most teachers only know two pre-concepts of friction: "a stationary object is subjected to static friction,and a moving object is subjected to sliding friction" and "friction must be resistance",and two pre-concepts of Newton’s third law: "interaction with the pre-concepts related to the magnitude of force" and "the interaction force is the same as the balance force",but do not understand other pre-concepts.And teachers basically don’t diagnose students’ pre-concepts before class.Through classroom observation of online and offline lesson examples,it is found that the completeness of the teacher’s implementation of the transformation of students’ pre-concepts in mechanics is not high enough,and the effectiveness is lower.Most teachers have not fully implemented the two important steps of manifestation and transformation of the pre-concepts.There are also differences in teaching content.Offline lesson examples are more complete in friction,but lower in Newton’s third law.In addition,teachers are not sufficiently aware of how to choose a more effective way of pre-concept visualization and how to rationally combine the visualization and transformation of pre-concepts to improve the effectiveness of teaching.For the manifestation of pre-concepts,teachers tend to use simple and direct questions.Regarding the transformation strategies of pre-concepts,teachers are still biased towards simple transformation strategies of creating life situations,and the teacher experiment strategies of offline lesson examples are not paid enough attention.Based on the investigation and research on teachers’ pre-concept cognition of mechanics,the following three suggestions are put forward for teachers’ professional development: teachers should strengthen the systematic study of pre-concept theory enhance the awareness of students’ pre-concept diagnosis,and improve the concept change teaching completeness and validity.