Understanding How Chemistry Teachers Transform Stoichiometry Concepts at Secondary Level in Lesotho

RESEARCH ARTICLE M. Makhechane and M. Qhobela, S. Afr. J. Chem., 2019, 72, 59–66, <http://journals.sabinet.co.za/content/journal/chem/>. 59 Understanding How Chemistry Teachers Transform Stoichiometry Concepts at Secondary Level in Lesotho Mamohato Makhechane and Makomosela Qhobela* § Department of Science Education, National University of Lesotho, Lesotho. Received 21 July 2018, revised 1 February 2019, accepted 2 February 2019. ABSTRACT This qualitative study sought to investigate how secondary level chemistry teachers transform and represent subject matter knowledge (SMK). The study drew its theoretical framework from the notion of Pedagogical Content Knowledge (PCK) that foregrounds the teachers’ ability to transform and represent SMK for students to understand the content presented. Seven qualified chemistry teachers participated in this study which used questionnaires, follow-up interviews, and lesson observations to collect data. The teachers were observed teaching the topic of stoichiometry to grade 11 students. Data analysis started with a coding system that resulted in themes of meanings suggested by teachers. The results show that chemistry teachers participating in the study were aware of different teaching strategies but their choice of those strategies was not informed by an attempt to transform the concepts. It is argued that teachers’ failure to transform concepts will have a negative impact on students’ understanding of these concepts. KEYWORDS Teaching strategies, PCK, chemistry, stoichiometry. 1. Introduction Underachievement in mathematics and science, both at primary and secondary levels, remains a challenge worldwide1,2 including in Lesotho.3 Many studies have discussed different factors resulting in underachievement in mathematics and science in developed and developing countries. For instance, there are researchers who have argued that underachievement in science is a result of unavailability and/or adequacy of infrastructure and quality of teaching.4 In Lesotho, achievement has been related to factors such as teaching experience of teachers, provision and attendance at professional development initiatives, and availability of teaching and laboratory materials.5 Another contributing factor is the choice and use of teaching approaches6. It has been argued that teachers tend to use chalk and talk strategies that inevitably socialize students into sitting down and watching the teacher,6,7 thus, becoming one of the contributing factors toward low student performance in science in general and in chemistry in particular. Research also shows that students in Lesotho sometimes progress to tertiary level having had no opportunity of doing basic experiments in chemistry.8 Literature shows that stoichiometry is considered a difficult and abstract topic to teach and learn in chemistry.9 Anecdotal evidence suggests that many teachers in Lesotho struggle with the teaching of stoichiometry and that many students do not perform well in stoichiometry questions in external examinations. Research elsewhere shows that stoichiometry demands special efforts from teachers to develop effective teaching strategies10, drawing on their topic specific Pedagogical Content Knowledge (PCK).11,12 This study explored the construct of PCK within the context of science education in Lesotho. The purpose of this study was to investigate how secondary level chemistry teachers transform and represent subject matter so that effective teaching and learning can occur. This paper responds to the following * To whom correspondence should be addressed. E-mail: research question: How do chemistry teachers in Lesotho transform subject matter when teaching stoichiometric concepts at senior secondary level so that these are easily understood by students? This research question was divided into three subquestions, namely: • What is the influence, if any, of the simplification of concepts on teachers’ choice of their teaching strategies? • What do the teachers do to simplify stoichiometry concepts in their lesson? and • What influenced teachers’ identification of big ideas of stoichiometry? Although there is literature on the issues of learner-centred teaching of science in Lesotho there was a need to understand teaching practice from a different perspective, namely PCK. The contribution of this study therefore is that of describing teaching strategies used in Lesotho to teach stoichiometry. 2. Literature Review 2.1. Pedagogical Content Knowledge Teaching for student understanding needs a special form of knowledge that will enable teachers to transform content knowledge into forms more accessible to students; this type of knowledge Shulman13 referred to as PCK. According to Shulman the development of PCK involves shifting: ‘from being able to comprehend subject matter for themselves, to being able to clarify subject matter in new ways, reorganize and partition it, clothe it in activities and emotions, in metaphors and exercises, and in examples and demonstrations, so that it can be grasped by students’ (p. 13) The central theme of the construct of PCK is the notion of making the subject matter comprehensible to students. Many researchers have studied aspects of PCK, and two of these are described below. ISSN 0379-4350 Online / ©2019 South African Chemical Institute / http://saci.co.za/journal DOI: https://doi.org/10.17159/0379-4350/2019/v72a9 RESEARCH ARTICLE M. Makhechane and M. Qhobela, S. Afr. J. Chem., 2019, 72, 59–66, <http://journals.sabinet.co.za/content/journal/chem/>. Mavhunga & Rollnick proposed a model which considers PCK as a construct at the level of the topic, namely Topic-Specific PCK.14 This model views transformation of content knowledge through five components; namely Learners’ Prior Knowledge, Curricular Saliency, What makes a topic easy or difficult to understand, Representations including analogies and Conceptual Teaching Strategies’.14 According to the researchers, if science teachers, when planning teaching, consider these components their teaching is likely to make concepts easier to understand. Another conceptualization of PCK refers to an amalgam of teachers’ different knowledge areas such as subject matter knowledge, pedagogical knowledge and contextual knowledge.15 According to this view the process of making the subject matter comprehensible to learners, requires bringing together different knowledge areas. For instance, some researchers argue that a teacher has to bring together five knowledge areas: the teacher ’s orientations to science teaching, knowledge of students’ understanding in science, knowledge of science curriculum, knowledge of instructional strategies and representations for teaching science, and knowledge of assessments of science learning.16 On the other hand, it has been argued that for the situation in Lesotho, physics teachers need to bring together, at the very least, subject matter knowledge, pedagogical knowledge and contextua (...truncated)