An analysis of the nature of visualisation objects in three Namibian grade 9 mathematics textbooks: a case study in Namibia
- Nghifimule, Selma Ndilipomwene
- Authors: Nghifimule, Selma Ndilipomwene
- Date: 2017
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6334 , vital:21090
- Description: Textbooks are a universal and central element of teaching and learning mathematics (Namibia. Ministry of Education [MoE], 2008). Steenpaß and Steinbring (2014) state that diagrams in mathematics textbooks are often used as Visualisation Objects (VOs) to enhance learning of mathematical concepts. VOs in textbooks are thus important teaching and learning tools (Fotakopoulou and Spiliotopoulou, 2008). This Namibian interpretive case study analysed the nature of VOs used in the three approved grade 9 Namibian mathematics textbooks namely: y=mx+c to success, Maths for Life 9 and Discover Mathematics 9. The VOs were analysed by using an analytical framework adapted from Fotakopoulou and Spiliotopoulou (2008). This analytic tool was specifically used to interrogate the following categories: the type of VOs, the roles of VOs, the relation of VOs to mathematical content, the relation of VOs to reality, and their properties. The 266 VOs under study were collected from the Algebra and Geometry chapters of each book. This study also included survey questionnaires with the 50 selected mathematics teachers, which sought their views and perceptions on the use of the identified VOs. In addition, the authors’ rationale in selecting the identified VOs used in their textbooks was sought through interviews. This research study is part of the “Visualisation in Namibia and Zambia” (VISNAMZA) project which seeks to research the effective use of visualisation processes in the mathematics classroom in Namibia and Zambia (Schäfer, 2015). It is hoped that this study contributes towards improving the quality of textbook evaluations, and design of suitable and more comprehensive assessment procedures in Namibia. It is also hoped that it creates a critical awareness of the roles of VOs in textbooks amongst teachers, inspiring them to help their learners interpret VOs effectively. It should also inspire potential authors to use suitable and appropriate VOs that enhance conceptual teaching and learning of mathematics. The study discovered that most of the VOs used in the selected textbooks align well with the mathematical content. The VOs can help make abstract ideas concrete, stimulate learning, simplify and clarify written texts. In addition, VOs can also be used as a tool for reasoning and an instrument for problem solving. The findings however also indicate that some of the VOs used are not self-explanatory; they are vague, unfamiliar and confusing, leading to misinterpretations by some learners. Another interesting finding was that some of the learners found it difficult to interpret VOs on their own without the help of the teacher.
- Full Text:
- Date Issued: 2017
- Authors: Nghifimule, Selma Ndilipomwene
- Date: 2017
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6334 , vital:21090
- Description: Textbooks are a universal and central element of teaching and learning mathematics (Namibia. Ministry of Education [MoE], 2008). Steenpaß and Steinbring (2014) state that diagrams in mathematics textbooks are often used as Visualisation Objects (VOs) to enhance learning of mathematical concepts. VOs in textbooks are thus important teaching and learning tools (Fotakopoulou and Spiliotopoulou, 2008). This Namibian interpretive case study analysed the nature of VOs used in the three approved grade 9 Namibian mathematics textbooks namely: y=mx+c to success, Maths for Life 9 and Discover Mathematics 9. The VOs were analysed by using an analytical framework adapted from Fotakopoulou and Spiliotopoulou (2008). This analytic tool was specifically used to interrogate the following categories: the type of VOs, the roles of VOs, the relation of VOs to mathematical content, the relation of VOs to reality, and their properties. The 266 VOs under study were collected from the Algebra and Geometry chapters of each book. This study also included survey questionnaires with the 50 selected mathematics teachers, which sought their views and perceptions on the use of the identified VOs. In addition, the authors’ rationale in selecting the identified VOs used in their textbooks was sought through interviews. This research study is part of the “Visualisation in Namibia and Zambia” (VISNAMZA) project which seeks to research the effective use of visualisation processes in the mathematics classroom in Namibia and Zambia (Schäfer, 2015). It is hoped that this study contributes towards improving the quality of textbook evaluations, and design of suitable and more comprehensive assessment procedures in Namibia. It is also hoped that it creates a critical awareness of the roles of VOs in textbooks amongst teachers, inspiring them to help their learners interpret VOs effectively. It should also inspire potential authors to use suitable and appropriate VOs that enhance conceptual teaching and learning of mathematics. The study discovered that most of the VOs used in the selected textbooks align well with the mathematical content. The VOs can help make abstract ideas concrete, stimulate learning, simplify and clarify written texts. In addition, VOs can also be used as a tool for reasoning and an instrument for problem solving. The findings however also indicate that some of the VOs used are not self-explanatory; they are vague, unfamiliar and confusing, leading to misinterpretations by some learners. Another interesting finding was that some of the learners found it difficult to interpret VOs on their own without the help of the teacher.
- Full Text:
- Date Issued: 2017
The impact of rangeland degradation on vegetation cover and soil quality in semi-arid communal rangelands of the Eastern Cape province, South Africa
- Authors: Maziko, Yonela
- Date: 2017
- Subjects: Communal rangelands -- South Africa -- Eastern Cape Land degradation -- South Africa -- Eastern Cape Vegetation management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15056 , vital:40159
- Description: This study was conducted to investigate the influence of degradation on vegetation and soil quality in two semi-arid rangelands in the Eastern Cape Province of South Africa. The study was undertaken in Kwezana and Esigingqini communal areas that showed signs id degradation. The assessment incorporated the soil and grass layer in different degradation levels, namely nondegraded, slightly degraded, moderately and severely degraded. The non-degraded has a sufficient amount of vegetation cover and species composition. The slightly degraded site consists of a few visible bare patches. The moderately degraded areas showed signs of active sheet erosion such as pedestals and a higher percentage of bare areas and the severely degraded area is characterized by dongas and gullies, with vast areas that have no ground cover or top fertile soil layer. Using a step point method, herbaceous species composition was determined within three transects from three plots 100 m x 40 m in each degradation level. The aboveground phytomass production was determined by harvesting herbaceous species within four randomly placed 0.25 m2 quadrats in each transect. Bare ground was determined by counting and recording the distance between tufts within each quadrat. Litter cover was determined by visual observation and rated on a scale of 1 to 5. A number of physical and chemical soil properties were used to quantify the effects of degradation on soil quality. To determine soil chemical properties, three soil samples were collected at a depth of 20 cm, in each plot and analyzed for pH, soil macro (N, C, K, P, Ca, Mg) and micro (Zn, Fe, Mn and Cu) nutrients. Soil compaction was determined using a soil pocket penetrometer. Readings were taken at 5 mm from 30 points placed at 1 m intervals and distributed in a randomly established straight line in each plot. Soil loss was determined using a rainfall simulator. Splash cups were filled with soil and placed under the rainfall simulator for 8 minutes per rainstorm at 360 mm-1 intensity. Results showed that at Esigingqini a total of 20 herbaceous species were identified, 17 of which were grasses. About 60percent of the identified grasses were Increaser II species, 15percent were Increaser II and 25percent Decreasers. In terms of palatability, 50percent of the grass species had poor palatability and the remaining had either average or high palatability. At Kwezana, 18 herbaceous species were identified of which 28percent were Decreasers and 61percent were Increaser II species. Half of the species had low palatability and only 28percent had high palatability. In both communal areas, litter cover was highest (P < 0.05) in the non-degraded areas followed by the slightly degraded sites and this was to be expected. Similarly, in both communal areas, there was a shift in species composition of decreasers and perennial grasses being replaced by annual species of poor quality and low palatability as the degradation levels increased. Results on soil chemical properties showed that the non-degraded areas had higher (P < 0.05) pH levels (8.5) than the severely degraded soils (5). A similar trend following a degradation gradient was observed for some soil nutrients such as N, P or Mg. Both the macro and micro nutrient concentrations were relatively higher (P < 0.05) in summer than in winter in both communal areas. Results on physical properties showed that soil loss and compaction were relatively lower (P <0.05) in the slightly degraded and non-degraded sites and increased with severity of degradation. In both communal areas, the severely degraded areas lost soil up to 1.1 t ha-1 due to degradation and the non-degraded areas had a soil loss of less than 0.8 t ha-1. The rate of soil loss between the severely and non-degraded areas is significantly different. The differences may be attributed to the differences in the vegetation cover which influences the rate of erosion on the various degradation gradients. These results suggest that both the grass layer and soil quality is negatively affected by degradation. Therefore, there is a need for land use practices that promote the sustainable use of rangeland resources. Such practices may include rotational grazing, reseeding, veld resting and fire. Measures to control the consequences of degradation and rehabilitate these deteriorated rangelands must be a priority.
- Full Text:
- Date Issued: 2017
- Authors: Maziko, Yonela
- Date: 2017
- Subjects: Communal rangelands -- South Africa -- Eastern Cape Land degradation -- South Africa -- Eastern Cape Vegetation management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15056 , vital:40159
- Description: This study was conducted to investigate the influence of degradation on vegetation and soil quality in two semi-arid rangelands in the Eastern Cape Province of South Africa. The study was undertaken in Kwezana and Esigingqini communal areas that showed signs id degradation. The assessment incorporated the soil and grass layer in different degradation levels, namely nondegraded, slightly degraded, moderately and severely degraded. The non-degraded has a sufficient amount of vegetation cover and species composition. The slightly degraded site consists of a few visible bare patches. The moderately degraded areas showed signs of active sheet erosion such as pedestals and a higher percentage of bare areas and the severely degraded area is characterized by dongas and gullies, with vast areas that have no ground cover or top fertile soil layer. Using a step point method, herbaceous species composition was determined within three transects from three plots 100 m x 40 m in each degradation level. The aboveground phytomass production was determined by harvesting herbaceous species within four randomly placed 0.25 m2 quadrats in each transect. Bare ground was determined by counting and recording the distance between tufts within each quadrat. Litter cover was determined by visual observation and rated on a scale of 1 to 5. A number of physical and chemical soil properties were used to quantify the effects of degradation on soil quality. To determine soil chemical properties, three soil samples were collected at a depth of 20 cm, in each plot and analyzed for pH, soil macro (N, C, K, P, Ca, Mg) and micro (Zn, Fe, Mn and Cu) nutrients. Soil compaction was determined using a soil pocket penetrometer. Readings were taken at 5 mm from 30 points placed at 1 m intervals and distributed in a randomly established straight line in each plot. Soil loss was determined using a rainfall simulator. Splash cups were filled with soil and placed under the rainfall simulator for 8 minutes per rainstorm at 360 mm-1 intensity. Results showed that at Esigingqini a total of 20 herbaceous species were identified, 17 of which were grasses. About 60percent of the identified grasses were Increaser II species, 15percent were Increaser II and 25percent Decreasers. In terms of palatability, 50percent of the grass species had poor palatability and the remaining had either average or high palatability. At Kwezana, 18 herbaceous species were identified of which 28percent were Decreasers and 61percent were Increaser II species. Half of the species had low palatability and only 28percent had high palatability. In both communal areas, litter cover was highest (P < 0.05) in the non-degraded areas followed by the slightly degraded sites and this was to be expected. Similarly, in both communal areas, there was a shift in species composition of decreasers and perennial grasses being replaced by annual species of poor quality and low palatability as the degradation levels increased. Results on soil chemical properties showed that the non-degraded areas had higher (P < 0.05) pH levels (8.5) than the severely degraded soils (5). A similar trend following a degradation gradient was observed for some soil nutrients such as N, P or Mg. Both the macro and micro nutrient concentrations were relatively higher (P < 0.05) in summer than in winter in both communal areas. Results on physical properties showed that soil loss and compaction were relatively lower (P <0.05) in the slightly degraded and non-degraded sites and increased with severity of degradation. In both communal areas, the severely degraded areas lost soil up to 1.1 t ha-1 due to degradation and the non-degraded areas had a soil loss of less than 0.8 t ha-1. The rate of soil loss between the severely and non-degraded areas is significantly different. The differences may be attributed to the differences in the vegetation cover which influences the rate of erosion on the various degradation gradients. These results suggest that both the grass layer and soil quality is negatively affected by degradation. Therefore, there is a need for land use practices that promote the sustainable use of rangeland resources. Such practices may include rotational grazing, reseeding, veld resting and fire. Measures to control the consequences of degradation and rehabilitate these deteriorated rangelands must be a priority.
- Full Text:
- Date Issued: 2017
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