This study examines the implementation of CEFR Basic User-level descriptors within a systematic instructional design framework to support learner-centered instruction and formative assessment in Korean elementary English education. Focusing on Grades 3 and 4, the study aligned CEFR’s four communicative functions—reception, production, interaction, and mediation—with the 2015 Revised National English Curriculum. A CEFR-based self-assessment tool was developed and administered before and after instruction to measure learners’ perceived communicative development. Findings revealed functional gains across multiple communicative domains, with variation in growth patterns depending on learner group and task type. K-means clustering identified three learner profiles—low-growth, reception-focused, and high-growth—which informed differentiated instructional strategies tailored to learner needs. The results demonstrate that CEFR-informed self-assessment, when combined with systematic instructional design, enhances curriculum coherence and supports data-driven pedagogy. This study provides empirical evidence on the practical integration of CEFR descriptors in primary classrooms, highlighting their potential to inform learner diagnosis and guide targeted instruction in localized educational contexts.

1. INTRODUCTION
2. THEORETICAL FRAMEWORK
    2.1. Systematic Instructional Design: The Dick and Carey Model
    2.2. CEFR-based Self-assessment and Learner Diagnosis
3. METHODOLOGY
    3.1. Participants
    3.2. Instruments
4. RESULTS
    4.1. Overview of CEFR-based Functional Growth
    4.2．Learner Clusters and CEFR-based Strategy Implications
5. CONCLUSION
REFERENCES
APPENDIX A
APPENDIX B

• Ji-Hye Jeon(Teacher, Namwon Wolrak Elementary School, 321 Yongseong-ro, Wolrak-dong, Namwon-si, Jeollabuk-do 55735, Korea)