Probing and provoking l2 development: The object of mediation in dynamic assessment and mediated development

Dynamic assessment (DA) refers to the administration of an assessment in which the conventional approach of observing learners as they independently complete tasks is abandoned and the assessor, or mediator, intervenes when learners experience difficulties, offering prompts, models, feedback, leading questions, and other forms of support. Such intervention is generally disallowed in formal assessments and even some approaches to classroom assessment on the grounds that it introduces measurement error by obfuscating the target of the procedure: learner knowledge and abilities. This objection is reasonable in so far as mainstream research in psychology and conventional practices in educational measurement conceive of abilities as discrete entities or traits that exist in the heads of individuals. On this view, assessment procedures are traditionally tasked with eliciting behaviors theorized to require use of the ability in question; the observed behavior, or test performance, is then interpreted as indicating the presence or strength of the ability being measured (Cronbach, 1990). DA, however, follows directly from Vygotsky’s (1998, p. 200) insight that exclusive focus on learner independent functioning “not only does not cover the whole picture of development, but very frequently encompasses only an insignificant part of it.” Vygotsky’s claim is based on his overall theoretical approach to understanding human consciousness, which as Lantolf, Poehner, and Swain (this volume) explain, is grounded in a philosophy of dialectical materialism. This orientation to science allowed Vygotsky to conceive his object of study in terms that revealed fundamental relations between phenomena usually regarded in isolation from, even in opposition to, one another. For Vygotsky, dualisms such as natural and cultural, internal and external, cognitive and emotive, past and future, and many others can be apprehended only when approached relationally, that is, by including their relations with other phenomena as definitive of what they are, what they have been, and what they may become. As Vygotsky (1978, p. 61) put it, his dialectical materialist psychology allowed him “to distinguish between the analysis of an object and of a process.”