CONTENT VALIDITY AND RELIABILITY OF THE FUNCTIONAL ABILITIES ASSESSMENT INSTRUMENT FOR PUPILS WITH SPECIAL EDUCATIONAL NEEDS

Functional abilities encompass adaptive skills essential for developing independence in daily tasks, with rapid acquisition occurring during early childhood. Assessing these abilities is crucial in education programs to ensure timely interventions for learners with additional support needs. Even though international functional assessment tools are available, there are few validated instruments for Malaysian primary school pupils with special educational needs. Therefore, this study evaluates the content validity and reliability of a newly developed functional abilities assessment instrument for Malaysian primary school pupils with special educational needs. A multidisciplinary panel of experts reviewed the instrument for fairness, relevance, clarity, and ease of understanding. The Scale-Level Content Validity Index (S-CVI) results demonstrated strong agreement among experts. Some items were removed or revised based on the Item-Level Content Validity Index (I-CVI) and modified kappa coefficients (*). The Rasch Measurement Model was applied across three domains to examine internal construct validity and reliability, revealing strong psychometric properties, particularly for the Body Functions and Activity and Participation sections. However, the Environmental Factors section showed slightly lower reliability indices, suggesting reduced measurement precision, though still within an acceptable range. The findings support the instrument’s potential in inclusive educational settings, while highlighting the need for additional large-scale validation before broader implementation.