Tan, Kim Chwee Daniel

Previous research (Taber, 1999, 2000a) has shown that A-level students in the United Kingdom had difficulty understanding the concepts involved in ionisation energy. The purpose of this study, which involved the use of interviews and written instruments, was to determine if Grades 11 and 12 students (16 to 19 years old) in Singapore had similar alternative conceptions and explanatory principles of the factors influencing ionisation energy as their A-level counterparts in the United Kingdom (U.K.), as well as to explore students' conceptions of the trend of ionisation energy across different elements in the Periodic Table. The results showed that many students in Singapore applied the same octet rule framework and conservation of force thinking to explain the factors influencing ionisation energy as students in the U.K. In addition, the students resorted to relation-based reasoning to explain the trend of ionisation energy across period 3 elements. The authors believed that the way ionisation energy was taught.and presented in textbooks could be the cause of students' difficulties in understanding ionisation energy. Teachers and textbooks need to focus explicitly on the effects of nuclear charge, the distance of the electron from the nucleus, the repulsion/screening effect of the other electrons present, and the interplay between these factors to explain the factors influencing ionisation energy and the trend in ionisation energy across period 3.

This paper describes the analysis of two commonly used secondary chemistry textbooks and two practical workbooks in Singapore to determine if the contents present are consistent with the concepts and prepositional knowledge, identified by the authors, as essential for the learning and understanding of O-level qualitative analysis. It was found that none of the textbooks and workbooks explicitly highlighted all the reactions involved in the procedures in qualitative analysis. The omission was likely to give students incomplete or little understanding of qualitative analysis, resulting in students adopting a cookbook understanding of qualitative analysis, resulting in students adopting a cookbook approach to qualitative analysis practical work.

Problems students encounter with understanding the abstract concept of chemical bonding, as revealed in previous research, are outlined. The development of a two-tier multiple-choice diagnostic instrument for assessing alternative conceptions about chemical bonding held by 14–16 year-olds is described. The instrument was administered to 119 chemistry students and the results analysed. The common alternative conceptions they were found to hold are listed and discussed. It was found that this instrument provided an easy-to-administer tool, providing results in a readily accessible form.

Categorisation of the entities of the world are important to help one make sense of the world and this process forms an integral part in the development of concepts. Inadequate clarifications and understanding of concepts in science may result in difficulties in the learning of science. In this paper, the authors discuss what the term, 'conceptual understanding', entails in the learning of science, using examples from the topics of 'Acids and Bases' and the 'Particulate Nature of Matter'. The authors also provide suggestions on how teachers can teach for conceptual understanding in the classroom as well as in the laboratory.

Grade 10 students in Singapore find qualitative analysis one of the more difficult topics in their external examinations. Fifty-one Grade 10 students (15 to 17 years old) from three schools were interviewed to investigate their perceptions about learning qualitative analysis and the aspects of qualitative analysis that they found difficult. The results showed that students found qualitative analysis tedious, difficult to understand and found the practical sessions unrelated to what they learned in class. They also believed that learning qualitative analysis required a great amount of memory work. It is proposed that their difficulties may arise from not knowing explicitly what is required in qualitative analysis, the content of qualitative analysis, the lack of motivation to understand qualitative analysis, cognitive overloading, and the lack of mastery of the required process skills.

This paper draws on Foucault to (a) describe the production of classroom discourse in relation to how ordering manifests within the discourse, and (b) to explicate how chemistry classroom discourses are not fixed but are the site of constant contestations of power as displayed in an eighty minute high school lesson on organic chemistry in Singapore. This microanalysis of discourse provides opportunities to reconstruct how teachers teach and dispels the notion that power is uniquely their sovereign possession. Classroom instruction is in fact a complex activity that coordinates power/knowledge production through communication. Examining classroom instruction through Foucaultian lenses uncovers the taken for granted nature of communication and illustrates the capillary relations of power and knowing.

STEM (science, technology, engineering, mathematics) hackathons have been conducted to offer opportunities for diverse participants to work collaboratively and intensely on tasks within a short period. However, most literature about hackathons does not offer theoretical discussions on the affordances of such learning contexts for school students. This paper reports on an inaugural event of a STEM capital-building program designed for students with relatively less access to STEM capital than their peers. Using epistemic infrastructure (EI) as the theoretical framework, we unpack the affordances of a STEM hackathon in terms of its cultural space, embodiments of artifacts, and practices (three tenets of EI) in building STEM capital. A total of 115 Grade 9 Singapore students from seven public schools participated in a purposeful 3-year STEM capital-building program. The data collected include video recordings of the activities, interviews with students and teachers, and photographs. The qualitative data were analyzed using prescriptive codes identified from the synthesis of the literature about epistemic infrastructure. The findings illuminated the three tenets of EI, and an additional tenet on social agency in EI was identified and discussed. The study contributes to the theorization of STEM curriculum and has implications for the design and implementation of informal STEM curriculum such as hackathons for STEM capital building.

This paper reports the findings of a study which investigated the role that educational research plays in influencing 29 Singapore pre-university (Grades 11 and 12) and secondary (Grades 9 and 10) chemistry teachers’ curricular and instructional decision making process. Twenty-five teachers were interviewed while four preferred to submit written responses to questions in the interview protocol. The findings indicated that factors which had an impact on the use of educational research by the teachers included those related to the teacher, school, research literature and time. This study can inform the chemistry educational research community of the issues that are important to teachers in their teaching of chemistry and use of educational research, and ways of working with teachers to address these issues.