Abstract
Valid assessment in special and inclusive education requires instruments capable of capturing the multidimensional learning outcomes of students with Special Educational Needs (SEN). This study examined the content validity of a newly developed, teacher-rated SEN outcomes instrument grounded in Bloom’s Taxonomy, which assesses cognitive, affective, and psychomotor development in school settings. Using the Content Validity Index (CVI) approach, eight experts in educational management, special education and educational assessment evaluated 19 items on a four-point relevance scale. Item-level (I-CVI) and scale-level (S-CVI/Ave and S-CVI/UA) indices were computed following established guidelines. Seventeen items achieved full agreement (I-CVI = 1.00), one met the acceptable threshold (I-CVI = 0.88) and one was removed for insufficient relevance (I-CVI = 0.75). Initial values (S-CVI/Ave = 0.98, S-CVI/UA = 0.89) exceeded recommended standards. After the item was removed, the final 18-item instrument reached S-CVI/Ave = 0.99 and S-CVI/UA = 0.94, indicating excellent content validity. The instrument shows strong conceptual coherence and alignment across all three domains. It offers educators a theoretically grounded framework to support Individualised Education Plans (IEPs), data-informed instructional planning and systematic monitoring of holistic learner development in inclusive settings.