Prospective pedagogy for teaching chemical bonding for smart and sustainable learning

As an important subject in the curriculum, many students find chemistry concepts difficult to learn and understand. Chemical bonding especially is important in understanding the compositions of chemical compounds and related concepts and research has shown that students struggle with this concept. In this theoretical paper based on analysis of relevant science education research, textbooks, and our classroom observations and teaching experiences, the authors argue that the difficulty in learning chemical bonding concepts is associated with the sequence (ionic, covalent and polar covalent bonding) in which students are taught because this sequence receives little support from constructivist theories of learning. Consequently, the paper proposes a sequence to teach chemical bonding (covalent, polar covalent and ionic bonding) for effective and sustainable learning. In this sequence, the concepts are developed with minimum reorganisation of previously learned information, using a format which is claimed to be easy for students to learn. For teaching these concepts, the use of electronegativity and the overlap of atomic orbitals for all types of bonding have also been stressed. The proposed sequence and emphasis on electronegativity and atomic orbital overlap meets the criteria for teaching and learning of concepts based on the psychology of learning including the theory of constructivism necessitating the construction of new knowledge using related prior knowledge. It also provides a better linkage between the bonding concepts learned at secondary and tertiary levels. Considering these proposed advantages for teaching, this sequence is recommended for further research into effective and sustainable teaching

The descriptive and explanatory nature of chemical diagrams does not guarantee understanding

Volunteer non-major chemistry students, taking an introductory university chemistry course (n= 17) were interviewed about their understanding of a variety of chemical diagrams. All the students&rsquo; interviewed appreciated that diagrams of laboratory equipment were useful to show how to set up laboratory equipment. However students&rsquo; ability to explain specific diagrams at either the macroscopic or sub-microscopic level varied greatly. The results highlighted the poor level of understanding that some students had even after completing both exercises and experiments using the diagrams. The connection between the diagrams of the macroscopic level (equipment), the sub-microscopic level (molecular) and the symbolic level (equations) was not always apparent to students. The results indicate a need for chemical diagrams to be used carefully and more explicitly to ensure the learner understanding.<br /

The modelling ability of non-major chemistry students and their understanding of the sub-microscopic level

This case study examined the ability of three first year non-major chemistry students to understand chemical concepts according to Johnstone&rsquo;s three levels of chemical representations of matter. Students&rsquo; background knowledge in chemistry proved to be a powerful factor in their understanding of the submicroscopic level. The results show that modelling ability is not necessarily innate, but it is a skill to be learnt. Each of the students&rsquo; modelling abilities with chemical representations improved with instruction and practice. Generally, as modelling skills improved so did students&rsquo; understanding of the relevant chemical concept. Modelling ability is described according to Grosslight et al.&rsquo;s three&ndash;tiered level and the ability to traverse the three levels of chemical representation of matter.<br /

Development of a Constructivist Model for Teacher Inservice.

In this paper, we consider a model for teacher inservice that is informed by constructlvlsm. Initially, we consider the criteria for identifying conceptual change, briefly examine research on the roles which teachers engage in when implementing innovations, and describing different knowledge bases needed m usmg teaching approaches informed by constructivist referents. Secondly, we describe an inservice programme for science teachers in one high school, and thirdly show how a five-stage model to introduce teaching/learning approaches informed by constructivism was developed

An Intervention Study Using Cognitive Conflict to Foster Conceptual Change

The study involved evaluating the efficacy of a conceptual change instructional programme involving cognitive conflict in (1) facilitating form 2 (grade 8) students’ understanding of algebra concepts, and (2) assessing changes in students’ attitudes towards learning mathematics, in a mixed quantitative-qualitative research design. The results showed that there was significant improvement in students’ achievement in mathematics and students’ attitude towards inquiry of mathematics lessons. Enjoyment remained high even though enjoyment of mathematics lessons showed no change. Changes in students’ understanding (from unintelligible to intelligible, intelligible to plausible, plausible to fruitful) illustrated the extent of changes in their conceptions. Finally, recommendations for future research are proposed

The Development of an Instrument for Assessing Students' Perceptions of Biology Teachers' Instructional Use of Diagrams

Science teaching involves using scientific diagrams to explain important concepts, to provide visual images, or to motivate students. However, teachers often wonder if their use of diagrams is effective in helping students learn science. This study aimed to help science teachers evaluate how students perceive their use of diagrams during instruction. Subsequently, we adapted an instrument to measure students' perceptions of science teachers' instructional use of diagrams based on Tuan et al.'s (2000) Student Perceptions of Teachers' Knowledge (SPOTK) questionnaire. The adapted instrument initially had four categories - teacher's instructional practice in using diagrams; teacher's use of multiple forms of scientific representations; teacher's use of diagrams in assessment practices; and students' understanding of and competence in using scientific diagrams. The instrument was administered to 215 Australian high school biology students in Years 9-10. Following factor analysis, 20 items remained in the final instrument and three scales were extracted - Instruction with Diagrams, Assessment with Diagrams, and Students' Diagrammatic Competency. The reliability of the total instrument Students' Perceptions of Teachers' Use of Biology Diagrams was 0.91 and the reliability of each category ranged from 0.65 to 0.90. This instrument is specifically related to the diagrammatic usage in biology lessons and, hopefully, with further research can be generalised to other science lessons. Future research will investigate the relationship between teachers' instruction with diagrams and students' understanding of them