Developing A Scientific Explanation Assessment For Primary School Students

In the past three or four decades,the essence of science has shifted from exploration and experimentation to explanation and argumentation.Science is a socialized cause where scientific groups work together to solve problems and explain natural phenomena,rather than conducting experiments on their own.Scientific theory is not discovered in the natural world,but is the explanation constructed to understand the world.However,in the science classroom at school,students often view "science" from the perspective of "positivism",and believe that scientific questions have "correct" answers,and the data undoubtedly points to consistent conclusions.Students can change their understanding of the nature of science by participating in the scientific explanation practiceAlthough the practice of scientific explanation is increasingly concerned by science educators,the evaluation and development of a large number of scientific explanations abroad is concentrated in middle schools,and there are fewer in primary schools.The tools for assessing the ability of scientific explanation in primary schools in China are missing.On the basis of the relevant scientific literature,this study based on the "evidence-centered design" theory,systematically developed a scientific explanation ability assessment toolFirst of all,based "evidence-centered design" theory,this study sorts out the relevant literatures of explanation and argumentation,determines the student model,task model and evidence model,and preliminarily formulates the topic of assessment tools and conducts expert review.Secondly,Using the cognitive interview method of vocal thinking and retrospective questioning,test the potential problems of the assessment tool and make corrections;again,the assessment tool will be tested by 320 fifth-grade students in Shanghai to conduct the content analysis and item analasis Finally,based on the formal test data,the quality of the survey is analyzedThe main conclusions and findings of this study include(1)The assessment of the ability of primary school students to explain scientifically can be done in the form of written scientific explanations,including the overall level and constituent elements.Based on the results of data analysis,these two aspects are reasonable and effective;(2)Based on the test data to revise the title,it is necessary to find evidence of the revised title from the two roles of teacher and student,quantitative and qualitative,and form a multi-party verification;(3)The reliability and validity of this assessment tool is good.This study provides evidence of multiple validation validity:preliminary preparation of topics based on the task model and curriculum standards,and review of the primary school science teachers and experts in the field of educational measurement to ensure content validity;cognitive interviews with students,testing whether students’ understanding of the item is consistent with the expectation,and the inconsistent topics are corrected one by one;in the trial phase,the poorly fitted topics of the item analysis can be verified and revised from the quality of the teacher interview and the student’s answer Guaranteed validity.The results of the formal test show that the revised title is well fitted,the difficulty and the degree of discrimination are in a reasonable range.The wright map verifies the rationality of the overall level of scientific explanation and provides evidence of test validity.In terms of reliability,the two researchers independently coded the sampled questionnaires in the trial.The coding consistency coefficient was high.Therefore,the tool developed in this study have good reliability and validity.