Research On The Evaluation Of Teachers’ Chemistry Teaching Practice Based On Handheld Technology Digital Experiments

In the information age,it is of great research significance to deeply analyze the current situation of chemistry teachers’ using handheld technology experiments in real classroom and evaluate its appropriateness.Firstly,this paper constructed an evaluation tool for teachers to carry out classroom teaching based on handheld technology experiments,which includes four dimensions of teaching background,experimental design,teaching behavior and teaching function.Differen levels are set for 11 secondary dimensions,representing the appropriateness of teachers’ teaching with handheld technology.Secondly,the evaluation tool was used to conduct coding statistics and scoring statistics for 30 lesson fragments which met the screening criteria and interception scope.Then the current situation and characteristics of teachers’ carrying out classroom teaching based on handheld technology experiments were summarized,and a quantitative evaluation of the appropriateness level of their teaching was also given.Finally,based on the analysis of the cases,suggestions for teaching improvement were put forward.The conclusions of this study are as follows.（1）In terms of teaching content,most teachers use handheld technology experiments to carry out courses related to "knowledge",especially the courses about four principles of chemical equilibrium,which account for the largest proportion.Much fewer teachers carry out courses related to "inquiry" and "application".In terms of teaching related variables,teachers generally performed well.It is suggested that teachers pay attention to the cognitive sequence of students’ knowledge and focus on explaining unfamiliar concepts but avoid complicated explanations.The level of teachers’ using sensors needs to be further improved.It is recommended to try to use multiple sensor probes in a same experiment so as to expand students’ thinking.（2）In terms of the assistive technology,the overall coverage of assistive technology in the classroom is low.Therefore,it is suggested that teachers increase the using rate of assistive technology and improve their own proficiency in combining teaching with handheld technology.In most cases,teachers mainly use demonstration experiments.It is also suggested that teachers combine handheld technology experiments with important experimental operation,core response principles or inquiry experiments to increase the number of “student experimens” form and improve students’ classroom participation and independent inquiry.（3）In terms of teachers’ behavior in experimental operation,they perform well.It is recommended to further improve their scientificity and rigor of experimental operation and attach great importance to the preparation of teaching alternate images.When it comes to teachers’ distribution of close and open questions,there are polarized situations.It is recommended that teachers further improve the rationality of distribution.In terms of assigning problems of three different cognitive levels,teachers pay more attention to the development of students’ intermediate thinking,while less to the development of advanced thinking.It is recommended to strengthen the training of students’ ability to use hand-held technology and to evaluate and innovate.（4）In the aspect of problem introduction and problem solving,teachers perform well and can give full play to the advantages of handheld technology itself.However,the level of appropriateness in "teacher-student interaction" and "educational value" remains to be further improved.It is suggested that teachers should avoid the form of one-way lectures based on handheld technology,but should develop more forms of multi-directional interaction with students,and pay more attention to the penetration of chemical experimental ideas and methods,and the cultivation of students’ chemical concepts.