The role of assessment is central to the current work in the field of self-regulation research, to the conceptualizations derived from empirical work, and to the operationalisation of its concepts in individual and classroom implementations. The various instantiations of the concept of self-regulation, all presuppose a detailed accounting of many different components, with each of them being represented by a variety of proxy variables which can be measured to establish the appropriate level at which the individual or group in question is functioning or performing. A review of the literature reveals a very diverse set of models and assessment instruments, many attempting to establish constructs with serious definitional problems, and conceptual overlaps. It is necessary then to establish their validity and the exact nature of their participation, as well as a clear differentiation between them. The assessment instruments which have been used so far are equally diverse, addressing the demands of the various components of the self-regulation models used and the different aspects emphasized in the research, including socio-cultural, cognitive, and volitional aspects. It is essential, to study carefully the relationship between assessment and the elements of the self-regulation process. This careful analysis will lead to a refinement of the instruments used, to the development of appropriate assessment methodologies and strategies, and to a richer conceptualization of the self-regulatory process (SR) based on empirical assessment data to inform the theory and model construction.