Browsing by Author "Clark, Jonathan"

Now showing 1 - 4 of 4
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    An ethnographic investigation into the development and trialing of more accessible text materials for second language teaching and learning in physical science
    (1993) Clark, Jonathan; Clark, Jonathan; Pickerill, Roy Thomas Alan; Young, Douglas
    This dissertation discusses the development of alternative science curriculum materials for a secondary schooling context where English, the medium of instruction, is a second language for both teachers and students. The research is located in an interpretative ethnographic framework and the data gathered during the classroom-based trialing of the materials highlights the vital role of language in the teaching and learning of school science. An interactive reading model coupled with a discourse approach to text analysis explores some of the language difficulties which black students experience with their science textbooks. That many students fail to develop adequate reading strategies is identified as lying at the heart of many learning problems. It is suggested that the key to comprehension is instruction from a base of more accessible text materials. Furthermore, although science practical work does not automatically advance students' knowledge and understanding, relevant and contextualised learning activities do equip students to become more self-directed and reflective learners of science.
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    Describing and understanding the enacted curriculum of selected Grade 10 Life Science teachers in the Western Cape, South Africa
    (2017) Petersen, Andrew John; Laugksch, Rudiger C; Clark, Jonathan
    This study was conducted in a school in the Western Cape, South Africa situated in a community where learners came from difficult social backgrounds. Previous research has alluded to the challenges faced by teachers equipped with inadequate skills and a lack of effective modelling or mentoring to implement a formal curriculum that is outcomes-based and learner centred. The focus of the study was to uncover the enacted curriculum (and the underlying reasons for the enactment) of four Grade 10 Life Sciences Teachers. This multiple case study is based on data collection strategies that included video and audio-transcripts of the lessons as well as the use of additional relevant documents such as, for example, notes from lesson observations, and learner notebooks. These data were coded using NUDIST and then further analysed using the Pedagogic Content Knowledge (PCK) evidence-reporting table (PCK ERT). Interviews were conducted before the teaching events to allow for content representations (CoRes) to be developed. Overall the teachers lacked planning and the habit of reflection in and of practice. Hence video-stimulated interviews conducted after the teaching events allowed for Pedagogical and Professional experience Repertoires (PaP-eRs) to be developed in order to describe (from a teachers' perspective) what teachers did and why they did what they did. Teachers had varying backgrounds and experience and displayed very individualised and different enactments of the curriculum but they all used a consistent didactic approach in their teaching. The absence of teacher efficacy and the lack of integration of the PCK components limited the transformation of the content in any meaningful way and hence resulted in weak PCK. The relevance of PCK ERT as a descriptive framework for PCK in the context of this research is questioned on epistemic grounds. Factors identified that constrained the enacted practices of teachers included teachers' belief, orientation, poor Subject Matter Knowledge (SMK), school context and their perceptions of learners.
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    Transforming content knowledge: a case study of an experienced science teacher teaching in a typical South African secondary school$$h[electronic resource]
    (2013) Toerien, René; Case, Jenni; Clark, Jonathan
    The unique knowledge that teachers possess Shulman called pedagogical content knowledge or PCK. In the following 25 years many scholars have conceptualised PCK, and only recently, with an international PCK Summit, have attempts been made to consolidate this field. South Africa’s primary and secondary public education system is continuously under scrutiny, as it continues to perform poorly in international benchmarking assessments. The need to understand what is happening in our classrooms, especially in science and mathematics, is now more important than ever. In response to this need, this study investigated the classroom practice of a dedicated and experienced science teacher over a period of three years, as she taught the organic chemistry section of the Grade 12 Physical Sciences syllabus. PCK was used as a lens to focus on how teacher knowledge manifests in practice.
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    Understanding scalability in distributed ledger technology
    (2020) Clark, Jonathan; Georg, Co-Pierre
    Distributed ledger technology (DLT) stands to benefit industries such as financial services with transparency and censorship resistance. DLT systems need to be scalable to handle mass user adoption. Mass user adoption is required to demonstrate the true value of DLT. This dissertation first analyses scalability in ethereum and EOS. Currently, ethereum 1.0 uses proof of work (PoW) and handles only 14 transactions per second (tps) compared to Visa's peak 47 000 tps. Ethereum 2.0, known as Serenity, introduces sharding, proof of stake (Casper), plasma and state channels in and effort to scale the system. EOS uses a delegated proof of stake (DPoS) protocol, where 21 super-nodes, termed ‘block producers' (BPs), facilitate consensus, bringing about significant scalability improvements (4000 tps). The trade-off is decentralisation. EOS is not sufficiently decentralised because the BPs yield significant power, but are not diverse. This dissertation conducts an empirical analysis using unsupervised machine learning to show that there is a high probability collusion is occurring between certain BPs. It then suggests possible protocol alterations such as inverse vote weighting that could curb adverse voting behaviour in DPoS. It further analyses whether universities are suitable BP's before mapping out required steps for universities to become block producers (leading to improved decentralisation in EOS)