Now showing 1 - 10 of 11
  • Publication
    Open Access
    Evaluating students’ understanding of chemical bonding
    (1999) ;
    Treagust, David F.
    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.
      3064  3450
  • Publication
    Open Access
    Qualitative analysis practical work: An instructional package
    (The Association for Science Education, 2004-06) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    Previous research has shown that grade 10 students in Singapore find quaiitative analysis practical work difficult to understand and carry out, and unrelated to the theory they had learned in class. This article describes a teaching package developed explicitly to teach the concepts, processes and thinking skills involved in qualitative analysis.
      429  1828
  • Publication
    Open Access
    Teaching and learning difficult chemistry topics: The need for a content framework
    (2000-09) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    Students have difficulties in learning certain topics in chemistry, for example, bonding, equilibrium, chemical reactions, electrochemistry, mole concept, and qualitative analysis. Possible reasons why students find such topics difficult include the abstract nature and the inter-relatedness of the concepts involved, the need to shift between four representation systems, and the involvement of process skills. A sound starting point for the teaching and learning of a difficult topic would be the clarification of the knowledge base that is required for the topic. Lists of conceptual and propositional knowledge statements and facts, process skills and metacognitive strategies, as well as concept maps should be drawn up to define the content framework for the topic. This would help teachers and learners to know what exactly is required for the topic. In this paper, the authors describe how they define the content framework for secondary chemistry qualitative analysis to facilitate the teaching and learning of qualitative analysis.
      2007  460
  • Publication
    Open Access
    Thinking and understanding in qualitative analysis practical work
    (2002) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    Students find qualitative analysis practical work difficult and are often uncertain about what they are doing in the laboratory. Students need to have tacit knowledge of the phenomena and reagents involved in qualitative analysis to understand the reactions that occur and the results that they get doing the experiments. Teachers also need to make explicit the links between the theory that students learn in class and the practical work that students do. In addition, teachers need to model the metacognitive strategies that students need in qualitative analysis practical work.
      120  1291
  • Publication
    Open Access
    It’s a displacement reaction because sodium ions are more reactive than zinc ions
    (Curtin University, 2002) ;
    Treagust, David F.
    Grade 10 (15 to 17 years old) students have difficulties in understanding ion-exchange reactions and complex salt formation involved in the tests for cations in basic inorganic chemistry qualitative analysis. Many students believed that when an insoluble hydroxide was produced from the reaction between an unknown cation and a hydroxide ion, a more reactive ion displaced a less reactive ion to form the precipitate. Students also explained that the reaction between several hydroxides and excess alkali as the precipitate dissolved when excess alkali was added because more solvent was added or that no new reagent was added and no further reaction was seen. Possible reasons proposed for such student conceptions included conceptual interference and perceptually-dominated thinking.
      190  1282
  • Publication
    Open Access
    Students’ understanding of acid, base and salt reactions in qualitative analysis
    (The Association for Science Education, 2003-03) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    A two-tier multiple-choice diagnostic instrument was used to determine 915 grade 10 students' (15- to 17-year-olds) understanding of the acid, base and salt reactions involved in basic qualitative analysis. The results showed that many students did not understand the formation of precipitates and complex salts, acid-salt/base reactions and thermal decomposition involved in qualitative analysis. This indicated that the usual method of teaching the topic might be ineffective in fostering its understanding. In response to this, an instructional package which emphasised the three levels of representation of the reactions was developed.
      260  1901
  • Publication
    Open Access
    The development of a two-tier multiple choice diagnostic instrument to identify secondary three and four students’ (14-17 years old) alternative conceptions in chemical bonding
    (1999-12) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    Chemical bonding is a topic which many secondary students find difficult to understand. The concepts in chemical bonding are abstract; one cannot see an atom, its structure and how it reacts with other atoms. Therefore there is great potential for the formation of alternative conceptions as students try to derive meaning from what is written in the textbooks or what is said by the teacher. Thus teachers need to be able to detect and diagnose the alternative conceptions of their students so that they can challenge these alternative conceptions, and help the students to acquire scientifically acceptable ones. Methods used to determine students’ understanding of concepts include concept mapping (Novak, 1996), interviews (Carr, 1996) and multiple choice diagnostic instruments (Treagust, 1988, 1995). However, multiple choice diagnostic instruments are more readily administered and scored than the other methods, and thus are particularly useful for classroom teachers. This paper describes the development of a two-tier multiple choice diagnostic instrument to identify Secondary Three and Four students’ alternative conceptions in basic chemical bonding.
      432  223
  • Publication
    Open Access
    A cross-age study on the understanding of the reactions involved in basic inorganic chemistry qualitative analysis
    (SEAMEO RECSAM, 2002) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    This cross-age study sought to determine the extent of secondary students’ (14-17 years old), junior college students’ (16 to 19 years old), and graduate trainee-teachers’ conceptions of the reactions involved in the testing of cations and anions in basic secondary qualitative analysis. The results showed that many of the participants in the study had little understanding of the reactions involved, and that alternative conceptions were prevalent among all groups of participants. The authors believe that the lack of understanding of the reactions involved in qualitative analysis is due to the requirements of the present qualitative analysis practical work assessment system which mainly emphasizes students’ observational skills.
      232  182
  • Publication
    Open Access
    Fundamental thermal concepts: An evaluation of Year 11 students’ conceptual understanding in everyday contexts
    (2009)
    Chu, Hye-Eun
    ;
    ;
    Loh, Lee Choon
    ;
    Treagust, David F.
    This research was conducted to investigate students' understanding of fundamental thermal concepts in everyday contexts. The 19 multiple-choice items in the questionnaire used in this study required written justifications for students' choice of responses. The items involving fundamental thermal concepts about heat, temperature, heat transfer and conduction were based on a previously developed questionnaire and from students' alternative conceptions derived from the research literature. The items which were entirely based on everyday contexts with scientific terminology avoided were administered to 80 Year 11 Singapore students. Four or five students from each class were interviewed in order to obtain additional information about their conceptual understanding and to probe the reasons they gave. Analysis of students' responses revealed several alternative conceptions of thermal concepts. Also, even though they held several acceptable scientific conceptions, many students had difficulties in applying thermal concepts in everyday contexts. The findings imply that classroom teaching needs to provide opportunities for students to make connections between scientific concepts and everyday contexts and to develop teaching strategies to help students better understand the related science concepts.
      162  514
  • Publication
    Open Access
    Secondary students’ perceptions about learning qualitative analysis in inorganic chemistry
    (Taylor & Francis, 2001) ;
    Goh, Ngoh Khang
    ;
    Chia, Lian Sai
    ;
    Treagust, David F.
    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.
    Scopus© Citations 8  247  511