Mediated Development: A Framework for Fostering the Internalization of Concept-Based Materials

Since its inception with Negueruela (2003) , concept-based language instruction (C-BLI) has incorporated approaches to organizing curricula around abstract language concepts that are initially presented to learners through specially designed materials (e.g., visuals, diagrams, and objects) and subsequently practiced in communicative activities to support concept appropriation by learners ( Lantolf & Poehner, 2024 ). Research associated with C-BLI has significantly expanded its scope to consider not only an array of linguistic features across a range of target languages ( Lantolf, Xi, & Minakova, 2021 ) but also the inclusion of other theories of psychological development that align with the principles of Vygotskian sociocultural theory (SCT). Regarding this latter point, the present study considers a strand of C-BLI research referred to as mediated development (MD) that is intimately informed by the work of Feuerstein and his associates in general cognitive education research (e.g., Feuerstein et al., 2015 ) as well as extensions of these programs in special education and academic content instruction ( Kozulin, 2024 ). MD distinguishes itself from other C-BLI approaches in that it provides a framework to support teacher efforts to guide learner engagement with linguistic concepts and their symbolic representation. Notably, dialogic mediation in MD includes activities that call forth psychological actions (e.g., labeling-visualizing, comparing, and materializing or encoding-decoding) that contribute to the learner's ability to think with conceptual materials and foreground the mediator's role in dialogically guiding learner use of conceptual materials to highlight the semantic possibilities available to them. We explore these characteristics of MD implemented in a C-BLI program ( Infante, 2016 ) focused on the English tense-aspect system. Transcribed interaction between an adolescent English learner and a mediator showcases the developmental possibilities that are brought about by the shifting emphases of dialogic mediation aimed at enhancing learner comprehension and use of concept-based materials over the course of a second language writing program.