The reproduction of Barbus Cf. Kimberleyensis (Pisces, Cyprinidae) in the Hardap Dam, South West Africa

Only one large yellowfish species occurs in the Hardap Dam, apparently closely related to Barbus kimberleyensis. Though smaller than this species in the Vaal River, it is nevertheless a valuable and abundant angling fish. After maturity, reached in females at 26 cm and in males at 18 cm fork length, females outnumber males by 9 :1 beyond 30 cm. Main spawnings occur between February and April, some four months later than in the Vaal River, being correlated with peak seasonal rains in both cases. A minor spawning later in the year is usual, with improved fry survival due to warmer weather conditions reducing the winter mortality of the earlier spawned young. Breeding sites are probably in lentic gravelly-bottomed areas within the dam. Egg production increases from 5-6 000 in 30 cm fish to ca 47 000 in 60 cm females, with strong relationship between cube of fish length and fecundity

First-year university students' conceptual understanding of electric circuits in relation to school and personal background

This paper reports a quantitative study about university students’ conceptual understanding of simple DC-circuits when entering firstyear physics at a South African university. The aim was to investigate how conceptual understanding relates to the students’ personal and school background. The conceptual framework was based on an existing model of the effectiveness of science education. Data were collected from 815 participants at a South African university. The conceptual understanding of DC circuits was measured in terms of performance in the well-known Determining and Interpreting Resistive Electric Circuits Concepts Test (DIRECT). Background information at school, classroom, and personal level was obtained with a questionnaire. Using Rash analysis, it was found that the students’ conceptual understanding relates significantly to the type of school attended, home language, previous achievement, their attitudes towards physics, and gender. However, contrary to expectations, the students’ conceptual understanding did not show a relationship with their exposure to practical work at school

Questions about answers : probing teachers' awareness and planned remediation of learners' misconceptions about electric circuits

This article reports an exploratory multi-case study on how science teachers understand and envisage addressing learners’ misconceptions about electric circuits. Four teachers from schools in and around a large South African city participated in the study. An open-ended questionnaire was designed in a novel way, questioning teachers about wrong answers they expected from their learners in test items suitable for Grade 9. Semi-structured interviews supported the questionnaire results, providing insight into the teachers’ understanding of learners’ misconceptions, and their ideas about how learners’ misconceptions should be addressed. Two of the teachers showed insight into learners’ conceptual difficulties, reflecting on learners’ thinking. Another teacher indicated some typical wrong answers but seldom understood the misconceptions leading to these mistakes, while the remaining teacher did not expect typical wrong answers corresponding to well-known misconceptions. All the teachers indicated that they would address learners’ mistakes mostly by practical work or demonstrations, but only two of the teachers also referred to the importance of developing conceptual understanding. Results suggest that these teachers’ understanding of learners’ misconceptions relates to their own subject matter knowledge. Furthermore, the study showed that the technique of questioning teachers about anticipated learners’ answers is a promising way of probing teachers’ understanding of learners’ misconceptions and the strategies they envisage using to address these misconceptions. It is recommended that learners’ misconceptions be addressed explicitly in teacher preparation and professional development programmes as an avenue to develop teachers’ pedagogical content knowledge (PCK).http://www.journals.co.za/ej/ejour_saarmste.htmlam201

The effect of a structured problem solving strategy on performance and conceptual understanding in physics : a study in disadvantaged South African schools

This study extended existing research on structured problem solving into disadvantaged South African classrooms. Sixteen disadvantaged urban South African high schools participated in a quasi-experimental study to investigate the effect of a structured problem solving strategy in physics on performance and conceptual understanding. The schools were disadvantaged with regard to standards set by the apartheid education system as well as by instruction in English, the second language of the students and most of the teachers. The problem solving strategy incorporated the use of different representations, group work, verbal arguments, written explanations, planning and interpretation of solutions. The strategy was implemented by a cascading model, where the researcher interacted with the teachers, while the teachers interacted with students. The treatment was non-disruptive of the normal school routine. The problem solving strategy was applied throughout the year while learning new content; there were no extra classes or additional work for learners. Normal classroom tests and examinations were utilized as sources of quantitative data. The treatment group outperformed the control group by 8 % in the midyear examination; this increased average score was statistically significant at the .001 level, indicating enhanced problem solving skills. Evidence of enhanced conceptual understanding was found by analyzing solutions presented in the midyear examination, videotaped problem solving and responses to questionnaires. Two new techniques were developed to assess conceptual understanding. Firstly, “solutions maps” were constructed for specific examination problems. These maps were visual representations of concepts, formulae, assumptions, substitutions and numerical answers presented by students. The popularity of various routes on the maps was compared for the two groups as a measure of differences in conceptual understanding. Secondly, a “conceptual index” was defined to quantify the extent to which a group of students used a conceptual approach in their solutions, as opposed to an algebraic approach. Learners and teachers regarded the structured problem solving strategy as a viable practice, they believed the students’ problem-solving skills were improved and they commented on the value of the strategy as a facilitator of understanding the language and concepts of physics. Teachers also believed that their own problem solving skills improved. Greeno’s model for scientific problem solving and reasoning was incorporated to explain the effect of structured problem solving on performance and conceptual understanding. Two complementary theories were offered to explain the results of the study. It was proposed that implementing the strategy fostered (1) the co-development of conceptual understanding and problem solving skills, and (2) the development of a conceptual approach to problem solving. Implementation of structured problem solving is a small intervention aimed at developing new habits of problem solving. In the South African context, it can make a significant contribution towards the enhancement of learning and teaching physics in disadvantaged schools.Thesis (PhD (Science Education))--University of Pretoria, 2007.Physicsunrestricte

Benefits and challenges of lesson study: A case of teaching Physical Sciences in South Africa

This study explored teachers’ experiences in the teaching of electricity and magnetism during a Lesson Study intervention. Using a case study research design, a sample of 4 physical sciences teachers was conveniently selected from schools in rural and suburban areas. Due to logistical challenges, the 4 participants were grouped into 2 separately functioning lesson study pairs. Data were collected through multiple sources including semi-structured interviews, observations of classroom teaching and Lesson Study meetings, field notes, participants’ initial lesson plans and reflective writings. It was found that collaboration through Lesson Study enhanced teachers’ professional teaching strategies, networking skills, lesson plan writing, classroom management, self-efficacy and positive attitudes towards teaching. However, challenges such as lack of time, lack of institutional support and insufficient instructional materials pose a threat to teachers’ participation in Lesson Study. It is therefore recommended that policy makers develop strategic plans to promote the use of Lesson Study as a school-based professional development initiative. Further research on Lesson Study in pre-service science teacher education may pave the way towards professional collaboration as a sustainable practice amongst science teachers. This may ultimately improve the performance levels of science learners in South Africa.Keywords: electricity and magnetism; lesson study; physical sciences; professional development; science teachin

Insig van onderwysers in wanopvattings oor eenvoudige stroombane

Hoewel daar heelwat internasionale navorsing gepubliseer is oor leerlinge se wanopvattings oor elektrisiteit, is daar weinig studies gedoen oor onderwysers se bewustheid van hierdie wanopvattings. Hierdie artikel doen verslag oor ’n gevallestudie om te ondersoek tot watter mate Suid-Afrikaanse onderwysers leerlinge se wanopvattings oor serie- en parallelstroombane verstaan, en tot welke mate dié insig geïntegreer word in onderwysers se pedagogiese inhoudskennis. Nege onderwysers uit staatskole is doelbewus geselekteer om aan die studie deel te neem. Kwalitatiewe data is uit vraelyste en onderhoude ingesamel. Daar is bevind dat onderwysers dikwels eenvoudige wanopvattings uitwys as oorsake van leerlinge se foute, maar dat wanopvattings wat verband hou met foutiewe analise, selde deur onderwysers genoem word. Verder is bevind dat onderwysers se kennis van wanopvattings gefragmenteerd is en nie met hulle begrip van basiese konsepte geïntegreer word nie. Die resultate toon dus dat hierdie onderwysers onvoldoende pedagogiese inhoudskennis betreffende wanopvattings oor serie- en parallelstroombane openbaar. Aanbevelings uit die studie is dat pedagogiese inhoudskennis rakende wanopvattings tydens onderwysersopleiding ontwikkel moet word.Many studies on learners’ misconceptions about electricity have been published internationally, but studies on teachers’ awareness of these misconceptions are few. This article reports on a case study to investigate to what extent South African teachers understand learners’ misconceptions about series and parallel circuits, and to what extent such understandings are integrated into their pedagogical content knowledge. Nine teachers from public schools were purposefully selected to participate in the study. Qualitative data were collected from questionnaires and interviews. It was found that teachers often indicate simple misconceptions as sources of learners’ mistakes, but that misconceptions related to incorrect analysis are seldom mentioned. Furthermore, it was found that these teachers’ knowledge about misconceptions was fragmented and not integrated with their understanding of basic concepts. The results indicate that these teachers display inadequate pedagogical content knowledge regarding misconceptions about series and parallel circuits. It is recommended that pedagogical content knowledge regarding misconceptions should be developed during teacher training.http://www.satnt.ac.za/am2016Science, Mathematics and Technology Educatio

Understanding science teachers' classroom practice after completing a professional-development programme: a case study

This article reports a study aiming to understand the classroom practice of four grade 7 science teachers following an in-service teacher-development programme. Such studies are needed to contribute to knowledge about the effectiveness of professional development programmes. Clarke and Hollingsworth’s model of professional growth was used as a theoretical framework. Data were collected by means of interviews, lesson observations and document analysis. It was found that each teacher experienced professional growth in a personalised way, such as increased confidence, improved content knowledge, teaching strategies, practical skills, and valuing professional collaboration. All the teachers reported that their classroom practices have improved. Lesson observations revealed that three of the four teachers were enthusiastic and engaged their learners in practical work. Challenges such as lack of resources, poor language skills, and lack of higher cognitive levels in activities and questions were observed for all the teachers. An adapted model of professional growth has been proposed to represent the professional development of science teachers in poorly resourced schools.http://www.ejmste.comam2018Science, Mathematics and Technology Educatio

Teaching electric circuits : teachers’ perceptions and learners’ misconceptions

An exploratory case study involving six grade 9 science teachers was undertaken to probe how teachers’ understanding of learners’ misconceptions relate to their perceptions about teaching simple circuits. The participants’ understanding of documented misconceptions in electricity were explored by means of a questionnaire, while their perceptions about teaching electric circuits were also explored in the questionnaire, followed by a semi-structured interview. Results were analysed using content analysis and interpreted using pedagogical content knowledge as a theoretical lens. The results indicated that understanding learners’ misconceptions did not always correlate with conceptual perceptions about teaching electric circuits. While fair understanding of misconceptions was demonstrated by teachers who studied Physics at undergraduate level, only those who also held qualifications in Education showed conceptual perceptions about teaching electricity. Teachers who did not study Science Education revealed technical perceptions, focused on facts, demonstrations and calculations. From these results, a developmental model for pedagogical content knowledge was proposed. It was recommended that teacher education programs should involve misconceptions and also facilitate the development of conceptual perceptions about teaching.The National Research Foundationhttps://link.springer.com/journal/111652020-02-01hj2018Science, Mathematics and Technology Educatio

A PARTICIPAÇÃO DAS ONG’S NOS ACORDOS MULTILATERAIS AMBIENTAIS: UMA ANÁLISE DA CONVENÇÃO SOBRE O COMÉRCIO INTERNACIONAL DE ESPÉCIES DA FLORA E DA FAUNA SELVAGENS AMEAÇADAS DE EXTINÇÃO (CITES)

Considering the need to democratization of the development and implementation of international environmental policies, notably by reference of the broad understanding of the environment as the interest of world society and cooperation object, paradigms that have become stronger with the acceleration of globalization, non-governmental organizations (NGOs) asserted themselves as legitimate actors increasingly influential in this process over the last two decades of the twentieth century. The rules and practices enshrined in various modern international institutions demonstrate enormous opportunities and participation rights, as this study reveals about the regime established by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). However, some barriers to participation may still be put to reflection for future developments, for example, the need for increased opening to participation in decision-making bodies, the actual function of the preliminary analysis of documents submitted by NGOs in official meetings, the need of distinction between national and international NGOs, the demand for equitable instruments for contracting services for international institutions and finally the lack of funding mechanisms for the representation of developing countries. In effect, anomalies exist and require solutions. However, because of the tendencies introduced by CITES, in particular the codification of new rules for participation based on strong historic consensus that NGOs are important partners in the formulation and implementation of international environmental regimes, the expectation is high in favor of new developments and paradigms for participation in multilateral environmental regimes.Diante da necessidade de democratização da elaboração e implementação das políticas internacionais ambientais, nomeadamente em função da ampla compreensão do meio ambiente como interesse da sociedade mundial e objeto de cooperação, paradigmas que se tornaram mais fortes com a aceleração do processo de globalização, as organizações não governamentais (ONG’s) se afirmaram como atores legítimos cada vez mais influentes nesse processo ao longo das duas últimas décadas do século XX. As regras e práticas consagradas em várias instituições internacionais modernas demonstram consideráveis oportunidades e direitos de participação, tal como este estudo revela à luz do regime estabelecido pela Convenção sobre o Comércio Internacional de Espécies da Flora e da Fauna Selvagens Ameaçadas de Extinção (CITES). Contudo, alguns obstáculos à participação podem ser ainda postos à reflexão para futuros desenvolvimentos, por exemplo, a necessidade de maior abertura à participação em órgãos de decisão, a real função da análise prévia de documentos encaminhados pelas ONG’s nas reuniões oficiais, a necessidade de distinção entre ONG’s nacionais e internacionais, a exigência de instrumentos de equidade na contratação de serviços para as instituições internacionais e, finalmente, a falta de mecanismos de financiamento para representação dos países em desenvolvimento. Com efeito, anomalias de fato existem e requerem soluções. Todavia, devido às tendências introduzidas pela CITES, em especial pela codificação de novas regras de participação com base no forte consenso histórico de que as ONG’s são importantes parceiras nas formulação e implementação dos regimes internacionais ambientais, a expectativa é alta em favor de novas evoluções e paradigmas para a participação nos regimes multilaterais ambientais

Intrinsic teaching challenges relating to practical investigations in some classrooms : an instructional design perspective

This article is based on the doctoral thesis of Fru Vitalis Akuma, "A professional development framework for supporting inquiry-based practical work in resource constrained classrooms". (URI: http://hdl.handle.net/2263/62900)The inquiry-based strategy in science education is widely recommended and incorporated in practical work. However, contextual and intrinsic teaching challenges associated with practical investigations (inquiry-based practical work), occur in resource-constrained physical sciences classrooms in South Africa. The intrinsic challenges have previously been identified from the perspective of the pedagogical content knowledge framework and the concerns-based adoption model. In this article we present a novel approach, investigating the intrinsic challenges from a viewpoint of instructional design. The multi-method technique was used to collect data which was analysed by combining the deductive and the inductive approaches in thematic analysis. The findings consist of intrinsic teaching challenges in the initiation, planning, and implementation phases of practical investigations. Examples of the challenges include practical work being considered to have a confirmatory role, inadequacies linked to addressing learner safety, and unfamiliarity with well-known instructional models. While new challenges were identified, the findings add a new perspective to intrinsic challenges relating to practical investigations in the context of physical sciences education in South Africa. Also, the findings enhance global knowledge about the complexity of intrinsic teaching challenges linked to practical investigations. In addition, the findings inform teacher support while suggesting lines of future research linked to practical investigations in resource-constrained physical sciences classrooms in South Africa and beyond.http://www.sajournalofeducation.co.zahj2023Science, Mathematics and Technology Educatio