This study aims to report on the psychometric properties of SCALE, a newly developed assessment instrument, that is based on the central curriculum for students with intellectual disabilities, using Rasch Analysis. Results indicated that the SCALE could classify students into at least 13 levels of abilities, and that the range of item difficulty was capable of stratifying students’ abilities into 8 to 11 attainment levels. The Rasch statistics demonstrated that the assessment results using SCALE had a high degree of validity and reliability. Its uni-dimensionality as an instrument to measure the attainment levels of the four Key Learning Areas in the central curriculum was also supported. Results from the Rasch Analysis showed that the SCALE measure is a well-validated instrument in identifying the differential levels of attainment. Based on the SCALE data, teachers can design learning materials and activities to match the performance levels of individual students. In addition, the use of the SCALE attainment descriptors to differentiate students’ attainment levels would enable teachers in schools to document progress of their students within an academic year. Subsequently, this enables them to reflect on their teaching effectiveness and make adjustments for the following year. 本研究旨在報告「融通學習成效量表」(SCALE)的心理測量數據特性。「融通學習成效量表」(SCALE)是為連接特殊學校與主流學校課程而研發出來的一項嶄新的評估工具。研究採用等級量尺模式分析法 (Rasch Analysis)‧結果顯示SCALE能把學生的學習能力表現至少可分13個不同程度;且其項目難度也能將學生能力分為8至11個學習能力表現水平級別。從統計數據顯示出SCALE擁有極高信效度。單一構念向度方面的數據亦顯示出SCALE能辨別出有特殊教育需要的學生於四個主要學習領域的學習能力表現之差異。故此,老師能使用SCALE的評估結果,去設計適合個別學生能力的教材及活動。此外,SCALE中的學生學習能力表現指標,亦能讓老師根據SCALE評估結果所提供的實證來衡量學生於每一學年間的學習進度,從而反思自己的教學效能,並在下一個學年為學生的教學作相應的調整。 [Copyright of Hong Kong Journal of Special Education is the property of Special Education Society of Hong Kong Ltd.. Full article may be available at the publisher's website: https://sites.google.com/a/seshk.org.hk/seshk-org-hk/c_publication]