The paper explores international comparisons of the extent of commonality or diversity in the main national external quality assurance frameworks for higher education. It has been suggested, from an European survey, that there are common features in national quality assurance frameworks (van Vught and Westerheijden (Quality Management and Quality Assurance in "European Higher Education: Methods and Mechanisms") 1993; Luxembourg, Commission of the European Communities, Education Training Youth). The paper extends the survey, tapping other comparative reports. These comparisons show that a "general model" of external quality assurance does not universally apply, but that most elements of it do apply in most countries. We conclude that the "general model" provides a starting point from which to map deviations. In each country,there may be specific additions of elements or omissions from the model, but more usually there are modifications or extensions of elements. These variations are determined by practicalities, the size of the higher education sector, the rigidity/flexibility of the legal expression of quality assurance (or the absence of enshrinement in law), and the stage of development from state control of the sector. Some additions to the "general model" are suggested. The paper also considers efforts to produce an international scheme for external quality assurance of higher education, and the applicability of the "general model" to the transfer of quality assurance frameworks from country to country.