Investigation of conceptual and language difficulties affecting the understanding of several mechanics concepts among some African teachers and students.
The results of national examination in matric and universities showed that African students were performing very poorly in their studies and examinations in science and in physics in particular. The objective in this study was to investigate some of the difficulties both African teachers and students, that meant African learners, had in understanding physics, specifically mechanics. The study consisted of investigation of two themes, namely, conceptual and language difficulties. Conceptual Difficulties were investigated by means of three questionnaire tasks. Task One investigated learners' understanding of the concepts of force, energy, power, momentum, speed and other related mechanics concepts in the context of boulders rolling down and up a mountain slope. Task Two investigated subjects' understanding of the force on a ball that was thrown up by the hand, went up to the highest position, and then turned and fell freely back to the ground. Task Three investigated learners' understanding of the positions where speeds, velocities, accelerations and forces were equal on a ball as it was going up and on its way down. The Pilot group, among whom the wide pilot work of this study was done through some haphazard questionnaire, consisted of pre-service and in-service teachers selected from the North East Free State Highlands which was regarded as an appropriate location with a number of institutions with the necessary research subjects, ,since it was neither much urban nor much rural. Intensive study and analysis was done on this pilot work and it led to some real research study to be conducted within a more "focussed" group, namely, the Student group. This Student group which consisted of the first year physics students on the Pietermaritzburg Campus of the University of Natal, was selected for purposes of comparison. Two kinds of Reference groups were devised: for the Conceptual Difficulties investigation the Reference group consisted of physics lecturers and professors from several universities. Their unanimous responses together were regarded as a memorandum through which to correct the responses of the study subjects. For the Language Difficulties investigation the Reference group consisted of African physicists from several universities. There was no unanimous consensus on their mechanics concepts translations into their vernaculars. Analysis of written results and interviews showed that African students experienced Conceptual Difficulties in mechanics. The Conceptual Difficulties were similar to those conducted in many other countries around the world by physics education researchers. The Language Difficulties were of two types. Firstly, a translation from a single mother tongue term into multiple English (the language of instruction) terms revealed a lack of clear concepts differentiation among the subjects. Secondly, there was no consensus, even amongst African physicists, as to which vernacular terms and English terms correspond. In addition, the interaction of the use of African vernaculars with an alternative conceptualisation seemed to have resulted to many of the research subjects believing in a quantity that is intrinsic to a person or object. This quantity had attributes of several different mechanics quantities, such as force, momentum, energy and power. Two tasks were used in the second theme where Language Difficulties were investigated. Translations of conceptual terms that were supplied in Task One and Task Three of the first theme were given and examined. The phenomenon of reverse translation from mother tongue to English was identified as a source of Language Difficulties due to the availability of limited words for these conceptual terms in the vernaculars spoken in South Africa. However, the effect language on the subjects' understanding of mechanics was not simply the result of the lack of vocabulary, the study also showed that the research subjects conceptualised physics concepts differently from physicists, this was revealed by analysing their use of both English and their vernaculars. The results of the investigations were then discussed and compared with those obtained by other research workers in similar studies around the world. Some approaches in teaching physics to African students in an endeavour to alleviate these unearthed difficulties were proposed and recommended in the conclusion. It was further encouraged that more investigations would show to appropriately and successfully instruct the African learners the physics concepts, since some institutions lately managed to produce African physicists and physics professors.