A reconceptualization of the zone of proximal development (ZPD) is proposed by introducing the notion of dialogicality and voice. Drawing on Bakhtin's semiotics, it is argued that the dialogical interactions occurring within the ZPD must be understood in a larger context to go beyond the visible and audible participants. More specifically, in addition to the first voice of the more capable participant and the second voice of the less competent participant, there is a third voice that serves as an immediate agenda of the ZPD. The third voice exerts its influence through the first voice by mediating the latter's intrapsychological functioning. The compatibility between the agenda of the third voice and the developmental goals of the zone determines whether the progression through the ZPD is enhanced or constrained. Standardized testing is given as an example of the third voice with a focus on its compatibility with the developmental goal of the ZPD.Keywords Vygotsky . The zone of proximal development . Socio-cultural theories of development . Dialogicality . VoiceOne of the major concepts proposed by Vygotsky, and the most often investigated and cited in educational literature (Ageyev 2003), is the zone of proximal development (ZPD). As Bruner (1987Bruner ( , 2004 notes, this concept is not only "stunning" on its own, but it also connects all of Vygotsky's ideas and thoughts regarding the "moving inward" of psychological functions. The implications derived from this theory for the teaching and learning process are also diverse (e.g., scaffolded instruction). A highly influential and welldeveloped theory as it is, like any theory, Vygotsky's ZPD may be revised for an improved Educ Psychol Rev (