This study sought to (a) investigate the effect of Van Hiele theory-based instruction on Grade 11 students’ geometric proofs learning achievement, (b) explore students’ views on their geometry learning experiences, and (c) develop a framework for better teaching and learning of Grade 11 Euclidean geometry theorems and non-routine geometric proofs. The study is based on Van Hiele’s theory of geometric thinking. The research involved a convenience sample of 186 Grade 11 students from four matched secondary schools in the Capricorn district of Limpopo province, South Africa. The study employed a sequential explanatory mixed-methods design, which combined quantitative and qualitative data collection methods. In the quantitative phase, a non-equivalent groups quasi-experiment was conducted. A Geometry Proof Test was used to assess students’ geometric proof construction abilities before and after the teaching experiment. Data analysis using non-parametric analysis of covariance revealed that students from the experimental group of schools performed significantly better than their counterparts from control group schools. In the qualitative phase, data were collected using focus group discussions and students’ diary records. Results revealed that the experimental group students had positive views on their geometry learning experiences, whereas students from the control group of schools expressed negative views towards the teaching of Euclidean geometry and geometric proofs in their mathematics classes. Based on the quantitative and qualitative data findings, it was concluded that in addition to organizing instruction according to the Van Hiele theory, teachers should listen to students’ voices and adjust their pedagogical practices to meet the expectations of a diverse group of students in the mathematics class. A framework for better teaching and learning of Grade 11 Euclidean geometry theorems and non-routine geometric proofs was thus developed, integrating students’ views and Van Hiele theory-based instruction. The study recommends that teachers should adopt the modified Van Hiele theory-based framework to enhance students’ mastery of non-routine geometric proofs in secondary schools.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-03-01T13:43:37Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) -Alessandra-Assad.pdf: 8992837 bytes, checksum: 39109f11342ebe17bfb50e8dcd0365a8 (MD5) / Made available in DSpace on 2018-03-01T13:43:37Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) -Alessandra-Assad.pdf: 8992837 bytes, checksum: 39109f11342ebe17bfb50e8dcd0365a8 (MD5) Previous issue date: 2017-12-14 / O presente trabalho teve como finalidade a investigação dos níveis do pensamento geométrico de estudantes de um colégio público da cidade de Paranaguá/PR, tendo como fundamentação teórica a Teoria de Van Hiele. Dessa forma para atingir o objetivo proposto utilizou-se das Tecnologias Educacionais, por meio de atividades desenvolvidas com o software Geogebra. Os participantes da pesquisa eram estudantes de três turmas do primeiro ano do Ensino Médio de um colégio público da cidade de Paranaguá. Estes realizaram 13 (treze) atividades correspondentes as 15 (quinze) habilidades indicadas no referencial teórico utilizado, divididas em três níveis: nível 0 (visualização), nível 1 (análise), nível 2 (dedução informal). A metodologia utilizada para esta pesquisa tratou-se da forma exploratória e aplicada. Pela análise dos dados coletados na resolução das atividades, pode-se concluir que o nível 0 foi atingido pela maior parte dos estudantes, uma menor porcentagem dos estudantes conseguiu atingir o nível 1. Em relação ao nível 2 pode-se verificar que foi o nível com maior dificuldade nas três turmas. Estes resultados apontam que os estudantes do colégio, onde se realizou a pesquisa, não detêm as habilidades visual, verbal, lógica, desenho e aplicação condizentes com o nível de ensino, segundo a Teoria de Van Hiele. Diante da evidente defasagem no conteúdo de Geometria apresentada pelos estudantes, pode-se dizer que além do objetivo proposto, esta pesquisa corrobora com os trabalhos de Pavanelo(1993), Lorenzato (1995), Passos (2000) e Barbosa (2003) entre outros que dissertam a respeito do abandono da geometria nas escolas do Brasil. Os resultados obtidos são preocupantes, pois esta defasagem acarreta a não compreensão dos conteúdos que serão trabalhado posteriormente. Assim, algumas ações no planejamento do processo de ensino-aprendizagem da geometria precisam ser repensadas. No âmbito local, pretende-se apresentar os resultados desta pesquisa à equipe pedagógica da escola, assim como aos professores da área de Matemática para que planejamentos e estratégias sejam organizados a fim de melhorar as habilidades do pensamento geométrico dos estudantes para que possam se aproximar do nível que é condizente a eles, segundo a teoria utilizada. / The present dissertation had the purpose to investigate the levels of geometric thinking of students of public school in the city of Paranagua/PR, having as theoretical foundation the Theory of Van Hiele. Thus, in order to achieve the proposed objective, it was used the Educational Technologies, through activities developed with Geogebra software. The research participants were students of three classes of the first year of the High School of a public school of the city of Paranaguá. They performed 13 (thirteen) activities corresponding to 15 (fifteen) skills indicated in the theoretical framework used, divided into three levels: level 0 (visualization), level 1 (analysis), level 2 (informal deduction). The methodology used for this research was exploratory and applied. By analyzing the data collected in the resolution of activities, it can be concluded that the majority of the students reached level 0 and a lower percentage of the students managed to reach level 1. In relation to level 2, it can be verified that it was the most difficult level to achieve in the three classes. These results point out the students of the school where the research was carried out do not hold the visual, verbal, logical, design and application skills that correspond to the level of education, according to Van Hiele Theory. In addition to the proposed objective, this research corroborates the works of Pavanelo (1993), Lorenzato (1995), Passos (2000) and Barbosa (2003) among others who talk about the abandonment of geometry in Brazilian schools. The results obtained are worrisome, as this lag causes the lack of understanding of the contents that will be worked on later. Therefore, some actions in the planning of the teaching-learning process of geometry need to be rethought. At the local level, it is intended to present the results of this research to the pedagogical team of the school, as well as teachers in the Mathematics area, so that the planning and strategies are organized in order to improve students' geometric thinking abilities so that they can approach the level that is appropriate to them, according to the theory used.

This study investigated the effect of integration of GeoGebra into the teaching of circle geometry on Grade 11 students’ achievement. The study used a quasiexperimental, non-equivalent control group design to compare achievement, Van Hiele levels, and motivation of students receiving instruction using GeoGebra and those instructed with the traditional ‘talk-and-chalk’ method. Two samples of sizes n = 22 (experimental) and n = 25 (control) drawn from two secondary schools in one circuit of the Vhembe district, Limpopo Province in South Africa were used. A pilot study sample of size n = 15, was carried out at different schools in the same circuit, in order to check the reliability and validity of the research instruments, and statistical viability. The results of the pilot study were shown to be reliable, valid and statistically viable. The study was informed by the action, process, object, schema (APOS) and Van Hiele theories, as the joint theoretical framework, and the literature search concentrated on technology integration, especially GeoGebra, in the teaching and learning of mathematics. The literature was also reviewed on the integration of computer technology (ICT) into mathematics teaching and learning, ICT and mathematical achievement, and ICT and motivation. The study sought to answer three research questions which were hypothetically tested for significance. The findings of this study revealed that there was a significant difference in the achievement of students instructed with GeoGebra compared to those instructed with the traditional teaching method (teacher ‘talk-andchalk’). The average achievement of the experimental group was higher than that of the control group. Significant differences were also established on the Van Hiele levels of students instructed with GeoGebra and those instructed without this software at Levels 1 and 2, while there were no significant differences at Levels 3, 4 and 5. The experimental group achieved a higher group average at the visualisation and analysis Van Hiele levels. It was also statistically inferred from questionnaires through chi-square testing, that students instructed with GeoGebra were more motivated to learn circle geometry than those instructed without the software / Mathematics Education / M. Sc. (Mathematics Education)

Euclidean Geometry is a challenging topic for most of the learners in the secondary schools. A qualitative case study explores the reasoning skills of ninth graders in the proving of congruent triangles in their natural environment. A class of thirty-two learners was conveniently selected to participate in the classroom observations. Two groups of six learners each were purposefully selected from the same class of thirty-two learners to participate in focus group interviews. The teaching documents were analysed. The Van Hiele’s levels of geometric thinking were used to reflect on the reasoning skills of the learners. The findings show that the majority of the learners operated at level 2 of Van Hiele’s geometric thinking. The use of visual aids in the teaching of geometry is important. About 30% of the learners were still operating at level 1 of Van Hiele theory. The analysed books showed that investigation help learners to discover the intended knowledge on their own. Learners need quality experience in order to move from a lower to a higher level of Van Hiele’s geometry thinking levels. The study brings about unique findings which may not be generalised. The results can only provide an insight into the reasoning skills of ninth graders in proving of congruent triangles. I recommend that future researchers should focus on proving of congruent triangles with a bigger sample of learners from different environmental settings. / Mathematics Education / M. Ed. (Mathematics Education)