Abstract
The development of core learning competencies in primary education is increasingly recognized as a foundational condition for students' readiness for independent inquiry, self-regulation, and meaningful participation in diverse classroom environments. Within this perspective, the present study examines the effectiveness of a UDL-based differentiated lesson architecture designed to systematically support the development of cognitive, self-regulatory, and communicative competencies in primary school students. The study employed a quasi-experimental design implemented over one academic semester in four general education schools in Almaty, Kazakhstan. The overall sample included 239 students in Grades 3–4 and 12 primary school teachers, while the controlled comparison was conducted on an analytical subsample of 124 students assigned to control and experimental groups. The intervention was organized through a structured lesson model integrating baseline diagnostics, differentiated task pathways, criterion-referenced formative feedback, and distributed roles in collaborative learning. To strengthen interpretive validity, the study combined pre- and post-testing, structured classroom observation, and analysis of formative assessment products. The results demonstrated consistent and educationally meaningful gains in the experimental group across all three competency domains, with particularly strong improvements in self-monitoring, reasoned participation, and collaborative engagement. The study contributes to current scholarship by conceptualizing differentiated instruction within a UDL-based design framework as a coherent and reproducible lesson architecture rather than a set of isolated pedagogical adaptations. Its practical significance lies in offering an implementable model for primary education that integrates accessibility, instructional variability, and formative regulation within everyday teaching practice.