Marginality in Inquiry-Based Science Learning Contexts: The Role of Exclusion Cascades.

Recent science education reforms have incorporated a range of Vygotskyan-inspired theories of learning, which has been conducive to studies of learners' participation in scientific practices. Yet, these theories vary in their emphasis on local sociocultural context's relationship to broader sociohistorical context as contributors to science learning, in some cases limiting these studies' ability to challenge adaptationist tendencies. The present study examined identity and motivation processes in an inquiry science context with the goal of better historicizing these processes by describing the phenomenon of exclusion cascades in relation to two backgrounded cultural-historical processes, alienation and the social division of labor. This microgenetic case study employed videorecorded observations of two small group collaborations in 7 th grade inquiry science classrooms. Exclusion cascades involve a series of peer interactions inside the group that produce a marginal position for a given group member and exceed the grain size of an interactional turn. Analysis of exclusion cascades allowed the mutual constitution of competence and belonging to be observed, highlighting an interplay between academic and peer status hierarchies in group functioning. Theoretical and practical implications are discussed with a focus on how future work can challenge adaptationism in science education.