Mapping the learning trajectories of physical sciences teachers' topic specific knowledge for teaching chemical bonding

Education in South Africa is a national concern and the training and professional development of teachers, especially in science and mathematics, has consequently been prioritised by the National Government. More than 60 percent of the teachers in South Africa are older than 40 years of age, which means that within the next 10-15 years many experienced teachers will exit the system, leaving a younger and less experienced cohort of teachers behind. This study aims to make explicit the learning trajectories of physical sciences teachers, specifically with respect to their knowledge for teaching chemical bonding, in order to support other teachers and thereby accelerating the route to expertise. Learning can be viewed as change, and change has a trajectory. Mapping the learning trajectories, and the significant events that influenced teachers' learning over time, can give insight into how the change had taken place. This study used a mixed methods approach within the pragmatic research paradigm to map learning trajectories for a group of 60 South African physical sciences teachers. Pedagogical content knowledge (PCK), the unique knowledge held by teachers, was used for the theoretical framing of the study. An adapted version of the Model of Teacher Professional Knowledge and Skill, including PCK, was used as an analytical framework. A measuring instrument for topic specific knowledge for teaching chemical bonding was designed and validated using the Rasch measurement model. Quantitative and qualitative analysis of the teachers' responses to the instrument and a grounded analysis of story-line interview data from ten purposively selected teachers were used to identify the factors that played a role in the development of the teachers' knowledge. A further qualitative analysis of PCK episodes from the interview data revealed how the above factors influenced the teachers' knowledge. Findings revealed that teaching the same content multiple times and at multiple grade levels, embracing changes in the curriculum as opportunities for learning, and further studies at tertiary level, especially completing post-graduate studies in education, all played a role in the teachers' perceived shifts in their topic specific knowledge for teaching (TSKFT). Three learning trajectories were identified for the teachers in this study: teachers shifted towards deeper conceptual understanding of the content and used more sophisticated explanatory frameworks; teachers shifted towards more integrated topic specific knowledge for teaching; and teachers shifted from being text book bound and teacher-focussed towards becoming more student-focussed in their approach to teaching. The findings from this study provide guidelines for professional development programmes in terms of differentiated support to teachers according to their career stages and the inclusion of content specific training programmes which makes teaching for conceptual progression explicit. A further recommendation includes encouraging teachers to embark on post-graduate studies in education as this played a pivotal role in shifting teachers' topic specific knowledge for teaching chemical bonding

Manufacturing strategy, product customisation and the marketing/manufacturing interface

The manufacturing strategy literature is reviewed and it is found to centre on content and process models. However, a number of other issues are present in the literature whose relationship to the central process and content models is less clear. These include the trade-off, focus, flexibility, and generic manufacturing strategies. It is noted that the manufacturing strategy literature does not fully address product customisation. The literature relating to the interface between marketing and manufacturing is found to concentrate either on the identification of conflict areas, or on strategic reconciliation between the functions. Writers in this field do give greater emphasis to product customisation. A case-study method is adopted for the research and the design involves four firms in varying industries. The firms manufacture fork-lift trucks, microswitches, telephone switching systems and diaries, respectively. The case-studies comprise quantitative and qualitative data, and each case chapter includes case-specific analysis. The analysis of all the cases finds that customisation has a very important effect on manufacturing performance. The firms have inconsistencies within their manufacturing strategies, but these are found to rest not only on the firms' manufacturing products with different volume requirements in the same plant, but also on the fact of some of the products being custom-designed. The interface between marketing and manufacturing is found to be more complex and variable than the literature would suggest. The role that customised products play in relationships with customers also varies, although this is inconsistently recognised by the firms.Based on the case-data, a model of product customisation is proposed. This incorporates customisation, flexibility, product architecture, the manufacturing strategy trade-off and the competitive criteria