A Comparative Study Of Knowledge Construction In BC Science And IGCSE Science

Textbooks play an important role in school education which disseminates knowledge and accelerates the socialization of individuals,so it is a hot issue in the research field of knowledge construction.Looking back to previous researches,current researches on knowledge construction of textbooks mainly focus on the knowledge construction in single-disciplinary textbooks or the comparative study of textbooks of different disciplines,but not much attention is paid to interdisciplinary textbooks.Therefore,it is of necessity to study it.STEM(Science,Technology,Engineering,Mathematics)is an education principle highly privileged in today’s education.Its core lies in the integration of four disciplines of science,engineering,technology,mathematics,and emphasis on practice.As an emerging education concept,STEM has been widely applied in science education.However,due to its interdisciplinary and practice-oriented nature,many scholars have questioned that the integration of disciplines may affect the legitimated construction of knowledge.This article attempts to compare knowledge construction in STEM-based science textbooks and subject-based science textbooks to explore the similarities and differences of knowledge construction.Based on the review of previous studies on knowledge construction of pedagogic discourse and features of STEM science textbooks,this thesis will take three aspects into comparison:the distribution and recontextualization of knowledge,and genre variation in activities.This thesis selects Canadian STEM science textbooks BC Science and Cambridge IGCSE Science textbooks to build a self-built corpus.Theories from systemic functional linguistics,Bernstein’s knowledge structure theory,and Maton’s legitimation code theory to establish a framework for analysis.Knowledge distribution is realized by analyzing the taxonomic relations of high-frequency terms;re-contextualization of knowledge is explored by semantic density and semantic gravity in the semantic dimension of legitimation code theory.Semantic density is reflected in lexical density,the ratio of word types to word tokens,and term frequency.Semantic gravity examines nominalization,the ratio of specific participants to generic participants,and the ratio of finite to non-finite processes.The similarities and differences of activities are obtained through a comparative analysis of genre.Through analysis,the major findings of this research include:(1)Both textbooks distribute knowledge by hierarchical knowledge structure,and build the knowledge system in textbooks through systematic taxonomic relations.The difference is that interdisciplinary concepts play an important role in the knowledge distribution of STEM-based science textbooks.Some interdisciplinary concepts appear repeatedly in textbooks and serve to organize discourse,in which way science discipline is placed in an integrated knowledge system.While in traditional science textbooks,the subjects are clearly distinguished and knowledge is not able to integrate.(2)In the comparison of the semantic density and semantic gravity of the two,no significant difference is found in the overall semantic density and semantic gravity of BC Science and IGCSE Science.Furthermore,as the grade increases,the semantic density and semantic gravity of BC Science remain consistent,which may result from the knowledge structure built by interdisciplinary concepts in STEM-based textbooks or the changing proportion of activities.(3)There are far more activities in STEM-based science textbooks than in subjectbased science textbooks.Genre variation lies in the selection of genres in activities.Practical activities in BC Science are likely to consist of operational or conditional procedures and explanations,while IGCSE mainly focuses on operational procedures.In addition,affected by the integration of disciplines,some of BC Science’s activities have phases such as designing,evaluating and optimizing.The study explores the knowledge construction in STEM-based science textbooks and subject-based science textbooks,which has enriched knowledge construction studies and the study of STEM-based science discourse from a linguistic perspective and is expected to have some practical significance for the design of science textbooks.