Development of the language subtest in a developmental assessment scale to identify Chinese preschool children with special needs.

This study reports on the development of the language subtest in the Preschool Developmental Assessment Scale (PDAS) for Cantonese-Chinese speaking children. A pilot pool of 158 items covering the two language modalities and the three language domains was developed. This initial item set was subsequently revised based on Rasch analyses of data from 324 multi-stage randomly selected children between 3 and 6 years of age. The revised 106-item set demonstrated adequate measurement properties, including targeting and uni-dimensionality. The revised 106-item set successfully discriminated preschool children in the three age groups, and between preschool children and their age peers with special education needs (SEN). Results from this study support the collection of normative data from a larger population sample of children to examine its accuracy in identifying language impairment in children with SEN. Test development procedures reported in this study provide insight for the development of language subtests in multi-domain developmental assessment tools for children speaking other varieties of Chinese.