David F. Treagust

Conceptual Change: A Powerful Framework for Improving Science Teaching and Learning

In this review, we discuss (1) how the notion of conceptual change has developed over the past three decades, (2) giving rise to alternative approaches for analysing conceptual change, (3) leading towards a multiperspective view of science learning and instruction that (4) can be used to examine scientific literacy and (5) lead to a powerful framework for improving science teaching and learning.

Development and use of diagnostic tests to evaluate students’ misconceptions in science

There is now a large body of research which examines students’ misconceptions in a variety of science subject areas. A problem exists, however, in applying the findings of this research to the classroom. One means of improving the application of misconceptions research is by the use of diagnostic tests which incorporate the findings of this research. A methodology for developing these diagnostic tests and the use of two such tests ‐‐ in chemistry (covalent bonding and structure) and in biology (photosynthesis and respiration in plants)‐are described. Analysis of the results of the tests given to class groups illustrate the ease of identification of misconceptions which can be subsequently addressed by the teacher.

A Typology of School Science Models.

Modelling is the essence of thinking and working scientifically. But how do secondary students view science models? Usually as toys or miniatures of real-life objects with few students actually understanding why scientists use multiple models to explain concepts. A conceptual typology of models is presented and explained to help teachers select models that are appropriate to the conceptual ability of their students. The article concludes by recommending that teachers model scientific modelling to their students, encourage the use of multiple models in science lessons, progressively introduce sophisticated models, systematically present in-class models using the Focus, Action and Reflection (FAR) guide and socially negotiate all model meanings.

Chemical education : towards research-based practice

Acknowledgements. General Preface J.K. Gilbert, O. de Jong, R. Justi, D.F. Treagust. J.H. van Driel. Foreword D. Gabel. A: Chemistry and Chemical Education. Preface to Section A J.K. Gilbert. 1. The Nature of Chemical Knowledge and Chemical Education S. Erduran, E. Scerri. 2. The History of Chemistry: Potential and Actual Contributions to Chemical Education J.H. Wandersee, P.B. Griffard. 3. Models and Modelling in Chemical Education R. Justi, J.K. Gilbert. 4. Learning Chemistry in a Laboratory Environment M.B. Nakhleh, J. Polles, E. Malina. B: The Curriculum for Chemical Education. Preface to Section B. 5. Chemical Curricula for General Education: Analysis and Elements of a Design W. de Vos, A.M.W. Bulte, A. Pilot. 6. The Roles of Chemistry in Vocational Education D. Corrigan, P. Fensham. 7. Informal Chemical Education S. Stocklmayer, J.K. Gilbert. 8. Context-based Approaches to the Teaching of Chemistry: What are They and What are Their Effects? J. Bennett, J. Holman. C: Teaching and Learning about Chemical Compounds. Preface to Section C D.F. Treagust. 9. The Particulate Nature of Matter: Challenges in Understanding in the Submicroscopic World A.G. Harrison, D.F. Treagust. 10. Bonding K.S. Taber, R.K. Coll. 11. Prblem-Solving in Chemistry G.M. Bodner, J.D. Heron. D: Teaching and Learning about Chemical Change. Preface to Section D R. Justi. 12. The Teaching and Learning of Chemical Equilibrium J.H. van Driel, W. Graber. 13. Teaching and Learning Chemical Kinetics R. Justi. 14. The Teaching and Learning of Electrochemistry O. de Jong, D.F. Treagust. 15. From Chemical Energetics to Chemical Thermodynamics M.J. Goedhart, W. Kaper. E: Developing Teachers and Chemical Education. Preface to Section E O. de Jong. 16. Exploring Chemistry Teachers Knowledge Base O. de Jong, W.R. Veal, J.H. van Driel. 17. Research and Development for the Future of Chemical Education J.K. Gilbert, O. de Jong, R. Justi, D.F. Treagust, J.H. van Driel. Notes about the Contributors. Index.

Current Realities and Future Possibilities: Language and Science Literacy - Empowering Research and Informing Instruction

In this final article, we briefly review and synthesize the science and language research and practice that arose from the current literature and presentations at an international conference, referred to as the first “Island Conference”. We add to the synthesis of the articles the conference deliberations and on‐going discussions of the field and also offer our views as to how such contributions can take place. These central issues—the definition of science literacy; the models of learning, discourse, reading, and writing and their underlying pedagogical assumptions; the roles of discourse in doing, teaching, and learning science; and the demands on teacher education and professional development in the current reforms in language and science education—provide points of departure for discussion of four possible new considerations to research in this field of endeavour that could contribute to a broader and productive scholarship and deeper and enriched understanding of both teaching and learning. These considerations, each from well‐established fields of research literature, are the need to develop support for a contemporary view of science literacy, the role of metacognition in science learning generally, the role of multiple representations in knowledge building and science literacy, and the need for more focused teacher education and professional development programmes.

Investigating a grade 11 student's evolving conceptions of heat and temperature

Many students enter physics courses with highly intuitive conceptions of nonobservable phenomena such as heat and temperature. The conceptions of heat and temperature are usually poorly differentiated and heat is often confused with internal energy. This article focuses on one students cognitive and affective changes which occurred during the Grade 11 topic of heat and temperature. The instruction used an inquiry approach coupled with concept substitution strategies aimed at restructuring alternative conceptions identified using pretests. A constructivist perspective drove both the teaching and research, and Ausubels theory of meaningful learning augmented the interpretive framework. The qualitative data comprising transcripts of all classroom discussions, student portfolios containing all of each students written work, and teacher/researcher observations and reflections were collected and interpreted to generate a case study for one student named Ken. Kens initial conceptual framework was undifferentiated with respect to heat and temperature. The course activities and concomitant use of concept substitution helped him differentiate these concepts and integrate them in a more scientifically acceptable way. A degree of affective and epistemological change was also identified as the course progressed. In-depth examination of the students prior, formative, and final conceptions showed that during this unit, the student progressively accepted greater responsibility for his learning, was willing to take cognitive risks, and became more critical and rigorous in both written and verbal problem solving.

Science teachers’ use of analogies: observations from classroom practice

The study was designed to examine how science teachers used analogies during their regular teaching routines to enable students to comprehend scientific concepts. A total of 40 lessons taught by seven different teachers were observed and analysed using an interpretive research methodology to develop four generalized observations. In this study the science teachers used few analogies, though both simple and enriched types were observed in their teaching. Interviews following classroom observations revealed that the teachers were knowledgeable about some of the beneficial and detrimental aspects of analogy use, and they considered that they used both analogies and examples as a regular part of their teaching, though it was observed that often they did not differentiate between examples and analogies. The research suggests that effective use of analogies in regular classroom science teaching needs to be based on a well‐prepared teaching repertoire of analogies, using specific content in specific contexts and...

The development of a two-tier multiple-choice diagnostic instrument for evaluating secondary school students’ ability to describe and explain chemical reactions using multiple levels of representation

A 15-item two-tier multiple-choice diagnostic instrument was developed to evaluate secondary students’ ability to describe and explain seven types of chemical reactions using macroscopic, submicroscopic and symbolic representations. A mixed qualitative and quantitative case study was conducted over four years involving 787 Years 9 and 10 students (15 to 16 years old). The instrument was administered to sixty-five Year 9 students after nine months of instruction to evaluate their use of multiple levels of representation. Analysis of the students’ responses demonstrated acceptable reliability of the instrument, a wide range of difficulty indices and acceptable discrimination indices for 12 of the items. The teaching program proved to be successful in that in most instances students were able to describe and explain the observed changes in terms of the atoms, molecules and ions that were involved in the chemical reactions using appropriate symbols, formulas, and chemical and ionic equations. Nevertheless, despite the emphasis on multiple levels of representation during instruction, 14 conceptions were identified that indicated confusion between macroscopic and submicroscopic representations, a tendency to extrapolate bulk macroscopic properties of substances to the submicroscopic level, and limited understanding of the symbolic representational system. [Chem. Educ. Res. Pract., 2007, 8 (3), 293-307.]

An Investigation into the Relationship between Students' Conceptions of the Particulate Nature of Matter and their Understanding of Chemical Bonding

A thorough understanding of chemical bonding requires familiarity with the particulate nature of matter. In this study, a two‐tier multiple‐choice diagnostic instrument consisting of ten items (five items involving each of the two concepts) was developed to assess students’ understanding of the particulate nature of matter and chemical bonding so as to identify possible associations between students’ understandings of the two concepts. The instrument was administered to 260 Grades 9 and 10 students (15–16 years old) from a secondary school in Singapore. Analysis of students’ responses revealed several alternative conceptions about the two concepts. In addition, analysis of six pairs of items suggested that students’ limited understanding of the particulate nature of matter influenced their understanding of chemical bonding. The findings provide useful information for challenging students’ alternative conceptions about the particulate nature of matter during classroom instruction in order to enable them to achieve better understanding of chemical bonding.

Evaluating Secondary Students’ Scientific Reasoning in Genetics Using a Two‐Tier Diagnostic Instrument

While genetics has remained as one key topic in school science, it continues to be conceptually and linguistically difficult for students with the concomitant debates as to what should be taught in the age of biotechnology. This article documents the development and implementation of a two‐tier multiple‐choice instrument for diagnosing grades 10 and 12 students’ understanding of genetics in terms of reasoning. The pretest and posttest forms of the diagnostic instrument were used alongside other methods in evaluating students’ understanding of genetics in a case‐based qualitative study on teaching and learning with multiple representations in three Western Australian secondary schools. Previous studies have shown that a two‐tier diagnostic instrument is useful in probing students’ understanding or misunderstanding of scientific concepts and ideas. The diagnostic instrument in this study was designed and then progressively refined, improved, and implemented to evaluate student understanding of genetics in three case schools. The final version of the instrument had Cronbach’s alpha reliability of 0.75 and 0.64, respectively, for its pretest and the posttest forms when it was administered to a group of grade 12 students (n = 17). This two‐tier diagnostic instrument complemented other qualitative data collection methods in this research in generating a more holistic picture of student conceptual learning of genetics in terms of scientific reasoning. Implications of the findings of this study using the diagnostic instrument are discussed.