This research set out to develop one or more conceptual models of diagnostic radiography based on the ways in which clinical radiographers themselves viewed their skills. The report analyses the historical relationship between radiographers and radiologists and the limited attempts at theory development prior to this research. This context is set against selected literature from nursing metatheory. This comparison is made since radiography had in part developed from the nursing profession and the historical and gendered background of both professions may be seen to be similar. •The methodology is largely qualitative and the use of computers for qualitative data analysis is discussed in some detail. The data collection was completed in three major phases- a diagnostic phase; a theory development phase and an applications phase, utilising several brainstorming groups and two questionnaires as well as action research in the third phase. In the diagnostic (first) phase of the research categories representing parts of the radiographic process were derived. Two models (or theoretical frameworks) were developed and their various concepts were explored and refined. In the second phase of theory development the research was extended to develop a statement of the role of the diagnostic radiographer and several concepts from the model were explored. In the final phase, the concept of holism was explored together with the relevance of the models for the education of student radiographers. In the final sections of the report there is a detailed evaluation of the potential impact of the models including a reflexive analysis. The conclusions are that the models provide a valid conceptual representation of the radiographic process and philosophy and that they have a role to play in education of student radiographers.