The purpose of the research documented in this thesis is to investigate how one particular approach to groupings in one primary school, commonly referred to as multi-age, enables and constrains the practices and actions of its individual teachers. This study is located in a literature that examines the potential that beliefs and belief systems offer for understanding how teachers make sense of, and respond to particular educational contexts. It will be of particular interest to the community of scholars who are investigating the uptake of curriculum innovations in the classrooms of individual practitioners. The philosophical framework underpinning multi-age schooling is significantly different from that operating within the traditional lock-step system. The conventional school organisation has the child move through a predetermined curriculum at a fixed pace, whereas multi-age classes require that teachers focus on needs-based teaching, thus adapting the curriculum to suit the individual student. As a result of this shift in emphasis, it has been common for teachers in multi-age schools to experience dilemmas caused by the dissonance between their own and the school’s assumptions about teaching, learning, knowledge and social relations. However, this clash of individuals’ beliefs and mandated practices is an under-researched area of scholarship particularly within multi-age settings, and is thus the focus of the present research. A framework based on the construct of beliefs and belief systems was used for understanding the personal and idiosyncratic nature of a teacher’s practice. Such a framework proposes that beliefs can be classified in terms of personal assumptions about self, relationships, knowledge, change and teaching and learning. These classifications, rather than being discrete dimensions acting in isolation, tend to be organised into a coherent and interdependent belief system or orientation. The notion of orientation was found to be a suitable framework within which to investigate the interplay between beliefs and practices over a two year period in one school context that is likely to provide challenges and opportunities for professional growth and development. Because the study focused upon the beliefs and practices of six teachers in a multi-age setting, elements of a qualitative approach to research were employed. The research design adopted for this study is grounded in an interpretative approach which looks for culturally derived and historically situated interpretations of the social world. Within this framework a case-study approach to research was used so as to reveal the interplay between the teachers’ beliefs and practices. The study found that the concept of orientations provides a suitable framework for understanding the personal and idiosyncratic nature of a teacher’s beliefs and practices. It was evident that beliefs about self, relationships, knowledge and change were highly significant in shaping the essential nature of teachers’ orientations. It was found that a summary label, based on these four beliefs, could be used to define the thematic nature of each teacher’s orientation. These recognisably different labels demonstrated that each teacher’s four beliefs were not just a pattern, but also a thematically defined pattern. It was also found that whilst some beliefs are thematically central other beliefs are not inherently thematic but are influenced in thematically derived ways. It was the configuration of these core/secondary beliefs that highlighted the importance of investigating belief combinations rather than discrete belief dimensions when attempting to understand the teacher as a person. It was also concluded that the teachers’ orientations in this study structured their practice in a way that was personal and internally consistent, indicating the dynamic coupling of beliefs and practices. It was clear that individual orientations, shaped by core beliefs, framed the challenges and possibilities that the multi-age ethos offered in varied and personal ways. In addition, the study found that the patterns of, and reasons for, change were complex and therefore it is unlikely that professional in-service will succeed if based on only one of the models of change proposed in the literature. The teachers in this study did not experience dilemmas as dichotomous situations but rather as complex and interrelated challenges to their whole belief system. Not all the teachers in this study approached the challenge of change in the same way. It was evident that individuals had constructed their own narrative for the need to change, and that this orientation tended to dominate the self-improvement agenda. Finally, this study demonstrated that not only the educational consequences of an innovation need to be taken into account, but also how well it is implemented in each classroom, and how compatible each teacher’s orientation is with the ethos underpinning the innovation.