Although scaffolding is an important and frequently studied concept, much discussion exists with regard to its conceptualizations, appearances, and effectiveness. Departing from the last decade's scaffolding literature, this review scrutinizes these three areas of scaffolding. First, contingency, fading, and transfer of responsibility are discerned in this review as the three key characteristics of scaffolding. Second, an overview is presented of the numerous descriptive studies that provided narratives on the appearances of scaffolding and classifications of scaffolding strategies. These strategies are synthesized into a framework for analysis, distinguishing between scaffolding means and intentions. Third, the small number of effectiveness studies available is discussed and the results suggest that scaffolding is effective. However, more research is needed. The main challenge in scaffolding research appears to be its measurement. Based on the encountered and described measurement problems, suggestions for future research are made.Keywords Scaffolding . Teacher-student interaction . Review . Primary and secondary educationThe concept of scaffolding has received a great deal of attention in educational research over the past few decades. An abundance of research on scaffolding in different contexts is thus the result. Scaffolding highlights one of the key aspects of children's learning, namely that it is often "guided by others" (Stone 1998a, p. 351).Scaffolding is typically associated with the socio-cultural theory of Vygotsky. Wood et al. (1976) adopted the scaffolding metaphor to explain the role that adults can play in joint problem-solving activities with children. Borrowed from the field of construction, where a scaffold is a temporary structure erected to help with the building or modification of another structure, the use of scaffolding as a metaphor within the domain of learning refers to the Educ Psychol Rev (2010) 22:271-296 DOI 10.1007 J. van temporary support provided for the completion of a task that learners otherwise might not be able to complete. This support can be provided in a variety of manners that for example includes modeling and the posing of questions for different subjects (e.g., science, social studies) at different ages. Stone (1993) described a Vygotskian-inspired analysis of scaffolding. According to Vygotsky, learning first takes place on a social (intermental) level before it takes place on an individual (intramental) level. In Stone's view, the student is not a passive participant in teacher-student interaction but scaffolding is seen as a fluid, interpersonal process in which both participants are active participants. Both participants actively build common understanding or intersubjectivity through communicative exchanges in which the student learns from the perspective of the more knowledgeable other.Because scaffolding is such a dynamic intervention finely tuned to the learner's ongoing progress, the support given by the teacher during scaffolding strongly depend...