Examining Teacher Effectiveness Through the Lens of Cultural-Historical Activity Theory in Multilingual Nigerian Classrooms

This study examines teacher effectiveness in the context of Nigeria's multilingual classrooms through the lens of cultural-historical activity theory, advancing a theoretically original and empirically grounded understanding of how teachers navigate linguistic diversity, cultural mediational tools, and institutional contradictions in their instructional practice. Nigerian classrooms are characterised by profound linguistic multiplicity, with students and teachers operating across indigenous languages, Nigerian Pidgin English, and Standard English in ways that create both pedagogical challenges and rich mediational opportunities. The study employs a multi-site cultural-historical activity theory analysis, involving ten secondary school teachers across Akwa Ibom, Enugu, Kano, and Ogun States, observed across two full academic terms. Data sources include structured classroom video analysis coded for activity theory mediational triangles, teacher reflection journals, student achievement outcomes, and systemic contradiction mapping interviews. Activity system modelling, contradictory tension analysis, and cross-case synthesis constitute the primary analytic methods. Results reveal that the most effective teachers systematically exploit multilingual code-switching as a pedagogical mediational tool rather than treating it as an instructional obstacle, achieving significantly superior student comprehension and engagement outcomes. Institutional contradictions between language policy mandates for English-only instruction and students' linguistic realities represent the most consistently disruptive tension in teacher activity systems. These findings advance cultural-historical activity theory as a framework for understanding teacher cognition in multilingual African classrooms. Curriculum policy in Nigeria should explicitly recognise translanguaging as a pedagogical resource. Keywords: cultural-historical activity theory, teacher effectiveness, multilingual classrooms, translanguaging, Nigeria.