An Investigation On The Similarities And Differences Of Geometric Optics In Junior Middle School Students

Before learning the formal physics concepts, the students tend to accumulatepreconceptions including some scientific concept and some non-scientific of things, which areinfluenced by their perception and experience of daily life; During the process of learning newphysics concepts, they are also prone to form new scientific concepts and non-scientific concepts.Many forms of these two types of non-scientific concepts form a certain architecture, known as“Alternative Frameworks”, which hinders the students from understanding and mastering thephysics concepts.Referenced on the junior high school geometry optics part of people’s education press someof the content. I designed the questionnaire “middle school students’ alternative framework aboutgeometrical optics(A)” and “middle school students’ alternative framework about geometricaloptics(B)”. I using the questionnaire to Qufu of Shandong province experimental middle schoolclass seven, grade seven and grade eight students of class four sampling survey and theinterview.The investigation about junior school freshmen indicated that there are11types of thealternative framework:(1) artificial light is not light source;(2) Optical effect equivalent tolight,light is made up of rays;(3) people’s eyes can emit the light spread along a straight line, socan’t clairvoyant object;(4) don’t need to follow certain rules, the transmission of light in thedirection of propagation will occur bending in the air;(5) light in the water spread along astraight line;(6) Shadow is real object;(7)Once in the camera as the real image of like hole;(8)Being flat mirror into the image and object in the same direction;(9)’levies as show in themirror surface;(10) as size and material object is associated with the distance of the mirror;(11)Bent chopsticks in the water is caused by water flow. The investigation about eighth gradersindicated that there are9types of the alternative framework:(1) equivalent effect on the opticallight;(2) people have been able to see objects, because the human eye is capable of emitting light;(3)light travels in straight lines in the water without dissemination deflection occurs in the samekind of uniform medium;(4) shadow is the actual existence of the object;(5) pinhole imagingsuch as small holes into the real image;(6)same plane mirror into the image and physicaldirection;(7)Being flat mirror into the image and object in the same direction;(8)’levies asshow in the mirror surface;(9) specular reflection looks better than the diffuse light.After the in-depth research questionnaire and analysis of interviews, I summarize ninereasons why the students have alternative frameworks in learning Interaction:(1)interference ofexperience from daily life;(2) negative impact of mindset;(3) wrong tuition and imagination;(4)the negative transfer of knowledge;(5) Inappropriate analogy;(6)the influence of improperteaching methods;(7) wrong interpretation of the physical concept of connotation and denotation.Based on these studies, this paper suggested four kinds of changes in teaching junior highgeometrical optics part of different vision:(1)clever design physics experiments, changing thedesign of effective alternative conceptions;(2) Design effective, heterogeneous transitionphase;(3)be explored different teaching, changing different idea;(4) contact real life, changingdifferent ideas.