Philosophiae Doctor - PhD / This thesis characterises and discusses two continuous coastal Southern Hemispheric (SH) atmospheric radon (222Rn) signals. Large-scale atmospheric circulation patterns are important components of the climate system implicated in driving catastrophic events such as extreme droughts and mega-wildfires and radon measurements at coastal sites provide valuable information on interactions of terrestrial and oceanic air masses on regional to hemispheric scales. The main collaborating SH atmospheric observatories in this study are located at Cape Grim (CGO, Tasmania, 1992-2017) and Cape Point (CPO, South Africa, 1999-2017). The radon signal from a high-altitude remote island oceanic site in the Northern Hemisphere Mauna Loa Observatory (MLO, Hawaii, 2004-2015) is also incorporated for comparison purposes. The CGO radon signal is the longest and most sensitive in current existence. A variety of statistical, spectral, trend, back-trajectory and trajectory density methods are utilized in this study to illuminate features of the datasets on multiple scales. Strongly skewed radon distributions occur, with a large number of events falling into a compact range of low values (corresponding to marine air-masses) and a smaller number of events spread over a wide range of high-radon values (continental air-masses). Making use of Fast Fourier Transform power spectral analysis, prominent periodicities are identified on diurnal and annual scales. Inter-annual variations in seasonal and diurnal radon and meteorological characteristics, indicating changes in the continental/oceanic atmospheric mixing state, are evident especially during the period from 2012 to 2017, perhaps associated with the strong El-Niño southern oscillation centred on 2015. A slow but systematic decline in CGO and CPO radon levels is evident over the dataset, associated with fewer continental and more marine air-masses impacting the coastal stations. The long-term trends observed in the atmospheric radon signal may indicate changes in SH circulation patterns over time, perhaps associated with climate change effects.

<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>

<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>

Magister Educationis - MEd (Mathematics and Science Education) / This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called ‘mixed methods’) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study. The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin’s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997). Further analyses were conducted on learners’ beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement). After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science–IK curriculum for the Natural Sciences subjects in South African schools.

Philosophiae Doctor - PhD / This research study examines those aspects of Indigenous Knowledge (IK) that could be socially and culturally relevant in the Western Cape Province, South Africa, for teaching meteorological science concepts in a grade 9 Social Science (Geography) classroom using dialogical argumentation as an instructional model (DAIM). The literature reviewed in this study explains the use of argumentation as an instructional method of classroom teaching in particular dialogical argumentation, combined with IKS (Indigenous Knowledge Systems), which in this study is seen as a powerful tool both in enhancing learners’ views and positively identifying indigenous knowledge systems within their own cultures and communities, and as tool that facilitates the learning of (meteorological) literacy and science concepts. With the development of the New Curriculum Statements (NCS) and the Curriculum and Assessment Policy Statements (CAPS) for schools, the Department of Basic Education (DBE) of South Africa acknowledges a strong drive towards recognising and affirming the critical role of IK, especially with respect to science and technology education. The policy suggests that the Department of Education take steps to begin the phased integration of IK into curricula and relevant accreditation frameworks. Using a quasi-experimental research design model, the study employed both quantitative and qualitative methods (mixed-methods) to collect data in two public secondary schools in Cape Town, in the Western Cape Province, South Africa. A survey questionnaire on attitudes towards, and perceptions of high school, of a group of grade 9 learners, as well as their conceptions of weather, was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study. An experimental group (E-group) of learners were exposed to an intervention - the results were recorded against a control group (C-group) that were exposed to no intervention. Both the E-group and C-group were exposed to a Meteorological Literacy Test (MLT) evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks underpinning the study, namely, Toulmin’s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997). The findings of this study revealed that: Firstly, the socio-cultural background of learners has an influence on their conceptions of weather prediction and there was a significant difference between boy’s and girls’ pre-test conceptions about the existence of indigenous knowledge systems within the community they live in. For instance, from the learners’ excerpts, it emerged that the girls presented predominantly rural experiences as opposed to those of the boys which were predominantly from urban settings. Secondly, those E-group learners exposed to the DAIM intervention shifted from being predominantly equipollent to the school science to emergent stances and they found a way of connecting their IK to the school science. The DAIM model which allowed argumentation to occur amongst learners seemed to have enhanced their understanding of the relevance of IK and how its underlying scientific claims relate to that of school science. Thirdly, the argumentation-based instructional model was found to be effective to a certain extent in equipping the in-service teachers with the necessary argumentation skills that could enable them to take part in a meaningful discourse. The study drew on the personal experiences and encounters from a variety of sources. These included storytelling-and sharing, academic talks with local community members recorded during the research journey, formal round table discussion and talks at international and local conferences, conference presentations, informal interviews, indigenous chats at social event-meetings, and shared experiences at IKS training workshops as a facilitator. These encounters lead to the formulation of the research study and occurred throughout the country in various parts of the Southern African continent including: Namibia, Zimbabwe, Malawi, Botswana, Tanzania and Mozambique.