Background: Since 2005, professionals in nine special schools collectively had developed an assessment tool called SCALES for all students regardless they are in special or mainstream schools in Hong Kong. Based on the concept of “one common curriculum for all”, SCALES is classified into the four Key Learning Area (KLA) strands of learning as in the mainstream curriculum framework, namely, Chinese, Science, Personal, Social and Humanities Education (PSHE) and Mathematics. This means that for the first time all of the students are being measured by exactly the same criteria irrespective of the ability or disability. Aims: In this study, we aim to apply Rasch measurement approach to analyzing a this innovative evaluation tool for children with special needs due to intellectual disabilities. Since Rasch measurement can convert ordinal measures into interval measures, the latter of which is fundamental for objective measurement in human sciences (Bond and Fox 2007). Methods: By using Winsteps, statistics such as infit and outfit mean square, person separation index, reliability, and dimensionality of the measurement scales are supported empirically. Results: The uni-dimensionality of the four major subject areas is supported with good psychometric properties such as high reliability and person separations that help differentiation of subjects. Selective applications of some items of these scales could be used by practitioners for quick screening and better intervention for care of children with special leaning needs. Conclusion: The scales are supported with both subject experts’ observation and quantitative evidence from sophisticated psychometric tests. Successful establishment of the instrument by subject experts is evident and quality-assured administration of the Rasch-based items in the future is recommended as the SCALES has proved to be a valid and reliable assessment measure for diverse learners.
|Publication status||Published - 2012|
CitationTsang, V., Bond, T. G., & Chow, J. (2012, August). Constructing Rasch-based measures for assessing academic attainment for students with intellectual disabilities. Paper presented at The Pacific Rim Objective Measurement Society Conference (PROMS 2012), Jiaxing University, Jiaxing, China.
- Rasch measurement
- Scale construction
- Students with intellectual disabilities
- Curriculum-based assessment
- Evaluation tool