Discussions relative to the quality of education often remain blurred by the lack both of clarity, as well as of a common understanding of what is actually meant by the term quality. Arguably, this has to do with the fact that, rather than an operational concept, quality in education is a notion which commands a seemingly intuitive understanding. As such, there is no single definition or approach, but rather diverse possible conceptualizations and multiple approaches, each based on widely differing assumptions. This paper thus proposes to take stock of some of the conceptualizations of the notion of quality in education, and of possible analytical approaches as well as their underlying assumptions. This appears crucial to UNESCO’s support of Member States as the notion of quality frames the organization’s efforts for the development of education worldwide. While this paper will focus on conceptualizations developed while monitoring progress towards the Education for All (EFA) goals, it will also refer to other approaches put forward to better understand and examine the quality of learning and the performance of education systems. In reviewing these, this paper offers three categories of frameworks in what might be called (i) the Learner-centred Approach, (ii) the Inputs-process-outputs Approach, and (iii) the Multidimensional Social Interaction Approach. The purpose of this paper is not to propose yet another model to conceptualize quality in education, but rather to chart a way through the conceptual maze by reviewing the array of existing approaches.