It is often assumed that the introduction of computers will transform teaching and learning in a primary classroom. However, in many classrooms, the effective use of computers to support teaching and learning is yet to be realised. The study described in this thesis is premised on the notion that simply providing access to computers will not change classroom processes and that the agent of change is a teacher's pedagogy and practice. This study initially examined the practices of a group of primary school teachers who were considered to be exemplary in the use of computers in their classroom. It then progressed to a focus on one teacher for indepth investigation of the strategies she used as she supported children to complete an extended computer-based task. Particular attention was given to the use of " scaffolding" as a teacher support strategy for children working with computers. The study adopted a qualitative methodology and was based on a Constructivist Inquiry model (Guba & Lincoln, 1989) with a Grounded Theory approach (Strauss & Corbin, 1990) for data analysis. It incorporated three phases of investigation which included: (a) a theoretical immersion, which was based on the literature; (b) a functional immersion, which examined the practices and understandings of eight teachers; and (c) a practical immersion, in which the support strategies of the focus teacher were observed during the implementation of the task over a period of eight weeks. These observations were enhanced by " stimulated recall" interviews where video vignettes were reviewed with the teacher. A detailed coding of teacher support strategies was developed during the study and eleven research constructs emerged from the final analysis of the data. These constructs represented the outcomes of the study and were grouped into four themes: (a) teacher expertise, (b) teacher understanding of support strategies, (c) the nature of scaffolding, and (d) the role of the computer. The results of the study suggested that a teacher needs to conscientiously select and implement strategies in order to support students working with computers. They also indicated that a teacher should plan for opportunities where teacher scaffolding can be used to support and extend students. Further, the results suggested that classroom teachers would benefit from knowing about scaffolding and how it can be implemented with children working with computers. The introduction of computers into the classroom invokes the need for conscious and deliberate changes to teacher pedagogy and practice to sure that effective use is made of the opportunities provided by the technology. Although teachers do require a measure of computer confidence, it seems that a teacher who successfully implements computers in the classroom is essentially focused on the implementation of effective teaching and learning practices. Therefore, it is important that pedagogy is foregrounded in any consideration of using computers in the classroom.