Educational Studies in Mathematics. https://doi.org/10.1007/s10649-026-10491-8
ABSTRACT: A design-based research project evaluating novel resources for culturally situated embodied geometry learning occasioned an opportunity for the researchers to consider conceptual relations between two prominent neo-Vygotskian theories, the semiotic–cultural theory of objectification by Luis Radford and instrumental genesis by Pierre Vérillon and Pierre Rabardel. We examine the case of Nath, an 11-year-old student who spontaneously created sign–tool hybridity in the form of a single artifact functioning fluidly as either a semiotic means of objectification or a cognitive instrument supporting his inquiry and argumentation. From an ecological standpoint, the hybridity arose through a perception–action coupling in which the artifact’s meaning and utility co-evolved with the unfolding cultural activity. Analyzing the artifact exclusively as either semiotic or instrumental may compromise the synthetic coherence of an enactivist theoretical modeling. Interfacing epistemologically affiliated theoretical perspectives on the ontology and cognitive function of educational resources may enable researchers to better understand the resources’ rich pedagogical affordances and, thereby, render these affordances accessible to students. Moreover, practicing epistemologically pluralist learning environments, where students are left to tinker available resources into new semiotic-cum-instrumental objects of their own device, in turn may afford researchers likewise to tinker available theories toward greater explanatory power.