The aim of this project was to research alternative conceptions that grades 11 and 12 high school physical science learners have about projectile motion. Their performance is compared with first year university physics students. A questionnaire was designed for grade 11 and 12 learners. The understanding of university students was assessed through ex post facto scrutiny of responses to a projectile question set in their mid-year examination. The results of this study were analyzed through the responses of the learners and university students. The study revealed that the grade 11 learners performed better than their grade 12 counterparts, though the same questionnaire was used for both groups. Such differences may be associated with the fact that projectile motion is taught during the grade 11 year of study. Grade 11 learners may therefore have a better memory recall of the formal teaching of the topic and associated concepts. By contrast, grade 12 learners might have resorted to a “re-understanding” of the various concepts as they have been acquired in their own world: these are what the literature refers to as, inter alia, alternative conceptions or naïve ideas. The performance of university students was also better than that of the grades 11 and 12 learners. This may be due to a maturity factor, as well as the way in which projectile motion was dealt with in their lectures. Arising out of our analysis, we shall make a number of recommendations as to how the topic might be better taught at the secondary level. Secondary educators need to be better informed about alternative conceptions research, and preventative and remedial activities that could be adopted.

Geologically young gullies have been proposed to be evidence of recent liquid water on Mars. This dissertation details work I have done to address issues surrounding the Martian gullies and recent water on Mars. In order to determine the elevations at which gullies occur, I created a set of Interactive Data Language programs and Unix C-shell scripts to coregister Mars Orbiter Laser Altimeter topography with high resolution Mars images. My scripts represent the first public method that does this. Recently, the Mars Orbiter Camera detected changes in the form of new bright deposits in two gullies. The High Resolution Imaging Science Experiment (HiRISE) camera detected more gullies with bright deposits. I used my scripts to identify some of the best candidates for liquid water formation based on their shallow average slopes. A Digital Elevation Model (DEM) was produced using HiRISE stereo images of my selected candidates in Hale Crater. I model two gullies with bright slope deposits in Hale Crater and find that both water-rich and sediment-rich flows could reproduce the bright deposits’ locations and morphologies. Since liquid water is rarely stable on Mars today, I suggest that dry flows formed the bright deposits. The channel gradient where flows deposit, the apex slope, can tell us whether a flow was likely dry and non-fluidized (slopes ~21°) or fluidized (shallower slopes). I measured the apex slope of 75 gullies located in five HiRISE DEMs. I find that 72% of the gullies studied were likely emplaced by a fluidized flow. I also find that modified gullies are more likely to have a fluidized emplacement than relatively fresh gullies. My results suggest that there is no evidence requiring water-rich flows in gullies today. Understanding the concept of water on Mars is crucial to understanding NASA’s Mars Exploration Strategy, “Follow the Water.” I undertook a study investigating alternative conceptions about water on Mars held by middle school science teachers to understand what they hear when scientists say “water on Mars.” All study participants had alternative conceptions about water on Mars. I suggest focus topics for space science education programs.

States of matter and phase changes are important topics in the teaching and learning of physical science. It is a common fact that learners find it difficult to understand the states of matter and phase changes. One of the main reasons is that learners do not abandon their own naive perceptions when the scientific concepts are taught. They do not connect their experiences outside the laboratory / classroom with their experience in science lessons. Learners consequently hold their own views even after instruction. According to the constructivist view on teaching and learning educators need to take learners' perceptions into account in the teaching of these topics. The first aim with this study was to determine learners' alterative conceptions about the states of matter and phase changes from a literature study. The second was to determine by means of an empirical study the alterative conceptions Grade 11 learners still hold after instruction of the topics. The empirical survey was conducted amongst a group of 110 Grade 11 learners studying physical science. A questionnaire was used to obtain information on this group of learners' knowledge on the states of matter and of phase changes after instruction of these topics. From the results of the questionnaire alternative conceptions could be identified. The results of the empirical study indicate that learners still have alternative conceptions about the states of matter and phase changes after instruction. Alternative conceptions were identified and recommendations on how to teach the states of matter and phase changes more effectively were made. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.

Learners of chemistry experience problems with the understanding of chemical reactions. One of the causes of this difficulty to understand chemical reactions seems to be that learners do not visualise them, or they do not know how to visualise them. The study aims at probing the learners' perceptions of visual models of sub-microscopic entities (atoms, ions, and molecules), to identify problems they encounter when trying to visualise and to understand chemical reactions. The empirical survey was conducted amongst 100 physical science Grade 11 learners from four high schools in the Bojanala West region near Rustenburg in the North-West Province, South Africa. The investigation was done by means of a questionnaire. The results of the questionnaire were used to identify alternative conceptions and problems that hampered learners' visualisation process. The results indicated that learners had problems with visualisation of the structure and the interaction of basic entities such as atoms, ions and molecules in chemical reactions. This had a negative effect on their understanding of chemical reactions and chemistry. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.

<p>In this study I will find out which thoughts and alternative conceptions pupils have about photosynthesis, decomposing and breeding. The method used was qualitative semi-structured interviews with pupils in preschool class and in the third grade. They were interviewed about what a flower needs in order to live, die and to propagate themselves. The result shows that the students have alternative conceptions about these issues. There are no big differences in the notions of the average classes. There is a relation between the children’s way of living and their notions.</p><p>The result shows that all 17 pupils know that the flowers need water and soil. Half of them know that it also needs sun. But only 2 pupils know that the flowers need sugar to live.</p>

In this study I will find out which thoughts and alternative conceptions pupils have about photosynthesis, decomposing and breeding. The method used was qualitative semi-structured interviews with pupils in preschool class and in the third grade. They were interviewed about what a flower needs in order to live, die and to propagate themselves. The result shows that the students have alternative conceptions about these issues. There are no big differences in the notions of the average classes. There is a relation between the children’s way of living and their notions. The result shows that all 17 pupils know that the flowers need water and soil. Half of them know that it also needs sun. But only 2 pupils know that the flowers need sugar to live.

States of matter and phase changes are important topics in the teaching and learning of physical science. It is a common fact that learners find it difficult to understand the states of matter and phase changes. One of the main reasons is that learners do not abandon their own naive perceptions when the scientific concepts are taught. They do not connect their experiences outside the laboratory / classroom with their experience in science lessons. Learners consequently hold their own views even after instruction. According to the constructivist view on teaching and learning educators need to take learners' perceptions into account in the teaching of these topics. The first aim with this study was to determine learners' alterative conceptions about the states of matter and phase changes from a literature study. The second was to determine by means of an empirical study the alterative conceptions Grade 11 learners still hold after instruction of the topics. The empirical survey was conducted amongst a group of 110 Grade 11 learners studying physical science. A questionnaire was used to obtain information on this group of learners' knowledge on the states of matter and of phase changes after instruction of these topics. From the results of the questionnaire alternative conceptions could be identified. The results of the empirical study indicate that learners still have alternative conceptions about the states of matter and phase changes after instruction. Alternative conceptions were identified and recommendations on how to teach the states of matter and phase changes more effectively were made. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.

Learners of chemistry experience problems with the understanding of chemical reactions. One of the causes of this difficulty to understand chemical reactions seems to be that learners do not visualise them, or they do not know how to visualise them. The study aims at probing the learners' perceptions of visual models of sub-microscopic entities (atoms, ions, and molecules), to identify problems they encounter when trying to visualise and to understand chemical reactions. The empirical survey was conducted amongst 100 physical science Grade 11 learners from four high schools in the Bojanala West region near Rustenburg in the North-West Province, South Africa. The investigation was done by means of a questionnaire. The results of the questionnaire were used to identify alternative conceptions and problems that hampered learners' visualisation process. The results indicated that learners had problems with visualisation of the structure and the interaction of basic entities such as atoms, ions and molecules in chemical reactions. This had a negative effect on their understanding of chemical reactions and chemistry. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.

Magister Educationis - MEd (Mathematics and Science Education) / A large percentage of South African learners held inadequate or alternative conceptions that might hinder them from developing a valid understanding of various scientific concepts and generalizations. This study explored the conceptions of Senior Phase learners on magnetism, chemical change of substances and the environment. More explicitly, the study attempted to investigate the influence of the learners" age, language and gender issues on their understanding of these scientific concepts. The study is underpinned by socio-cultural constructivism as espoused by Vygotsky (1978). The research sample comprised 250 Senior Phase learners (grades eight and nine) from secondary schools in the Metro Central District in the Western Cape. The study used the following six research instruments for data collection: Science Achievement Test (SAT), Context Test, Cloze Test, Picture Test, Science Vocabulary Test and an interview schedule. The tests were administered to all the participants while the interview was conducted with six participants.This study was a descriptive research of a survey type and data was collected and analyzed using both quantitative and qualitative methods.The data collected was analyzed quantitatively using the Statistical Package for Sciences (SPSS) in order to obtain descriptive statistics that were used to explore the conceptions of senior phase learners in magnetism, chemical change substances and the environment in the Metro Central district while data from the tape recorder and notes taken during the interview, were analyzed qualitatively.

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