Other researchers, however, such as Moll and Whitmore (1998), haveargued that the ZPD concept can be useful in classroom contexts. Theysuggest that traditional conceptions of ZPD based on dyadicinteractions are, indeed, too narrow and do not account for thesocio-cultural dimensions of the classroom as a context for learning. Moll and Whitmore (1998) use examples of children's written work todemonstrate how one particular class teacher provided a series of‘authentic social contexts' within which her bilingual students wereable to explore the myriad of oral and written conventions of theirlanguages. Moll and Whitmore (1998), thus, suggest that it isunnecessary to view ZPD simply in terms of the characteristic of eachindividual child but that classrooms can accommodate ‘collective'ZPDs. They redefine the ZPD as “a zone where children can beencouraged to participate in collaborative activity within specificsocial (discourse) environments” (Moll and Whitmore, 1998, p. 132). They conclude that classrooms should be viewed as socio-cultural systems where, over time, teachers and students build up a history of shared understandings and generate new knowledge.