Catherine Lam

Development of a preschool developmental assessment scale for assessment of developmental disabilities

The aim of this paper was to describe the development of the cognitive domain of the Preschool Developmental Assessment Scale (PDAS) for assessment of preschool children with developmental disabilities. The initial version of the cognitive domain consisted of 87 items. They were administered to 324 preschool children, including 240 children from preschools and 84 children with developmental disabilities. Initial Rasch analysis results indicated that the fit statistics of 42 of the items were outside the acceptable range. Based on the fit statistics and considering the overall structure of the scale, the revised version consisted of 40 items and this version conformed to the Rasch expectations. The revised 40-item scale could differentiate between children with typical development and children with developmental disabilities. It could also differentiate between children from different age groups. The internal consistency estimate (KR-20) was .93. The cognitive domain of the PDAS is considered a promising developmental assessment tool for assessment of developmental disabilities.

Exploring reading-spelling connection as locus of dyslexia in Chinese.

This paper advances the argument that in learning to read/spell Chinese characters and words, it is important for learners to understand the role of the component parts. These constituents consist of phonetic and semantic radicals, or bujians, made up of clusters of strokes in their proper sequence. Beginning readers/spellers need to be sensitive to the positional hierarchy and internal structure of these constituent parts. Those Chinese children diagnosed with developmental dyslexia tend to have more difficulties in spelling Chinese characters and in writing to dictation than in reading. A lexical decision study with two groups of tertiary students differing in their Chinese language ability was carried out to test their efficiency in processing real and pseudo characters as a function of printed frequency of the characters, and the consistency of their component semantic radicals. There is some evidence that even for adult readers differing in their Chinese language ability, lexicality, frequency of characters and the consistency of the semantic radicals affect accurate and rapid character identification. Suggestions for research and teaching approaches are made to enhance the analysis and synthesis of the phonetic and semantic radicals to promote efficient reading and spelling in Chinese.

The validation of a scale to measure cognitive development in Chinese preschool children.

The present study aimed to evaluate the reliability and validity of the cognitive sub-test of the Preschool Developmental Assessment Scale (PDAS) for Hong Kong Chinese children. Participants included 378 children (189 boys and 189 girls) aged 3-6 years old, with 324 children with typical development and 54 children with developmental disabilities. They were administered the cognitive sub-test of the PDAS and the Wechsler Preschool and Primary Scale of Intelligence - Revised (WPPSI-R). The PDAS cognitive sub-test total scores correlated positively with the WPPSI-R scores. It could differentiate children from different age groups, with younger children attaining significantly lower scores than older children. The sub-test could also differentiate children with typical development from those with developmental disabilities, with the latter attaining significantly lower scores. The sensitivity and specificity were around 80%. Internal consistency (KR-20) was .93 and test-retest reliability was .81. The cognitive sub-test of the PDAS was found to be a promising screening tool for the identification of preschool children with developmental disabilities.

The Joint Effects of Risk Status, Gender, Early Literacy and Cognitive Skills on the Presence of Dyslexia Among a Group of High‐Risk Chinese Children

This study sought to examine factors that are predictive of future developmental dyslexia among a group of 5-year-old Chinese children at risk for dyslexia, including 62 children with a sibling who had been previously diagnosed with dyslexia and 52 children who manifested clinical at-risk factors in aspects of language according to testing by paediatricians. The age-5 performances on various literacy and cognitive tasks, gender and group status (familial risk or language delayed) were used to predict developmental dyslexia 2 years later using logistic regression analysis. Results showed that greater risk of dyslexia was related to slower rapid automatized naming, lower scores on morphological awareness, Chinese character recognition and English letter naming, and gender (boys had more risk). Three logistic equations were generated for estimating individual risk of dyslexia. The strongest models were those that included all print-related variables (including speeded number naming, character recognition and letter identification) and gender, with about 70% accuracy or above. Early identification of those Chinese children at risk for dyslexia can facilitate better dyslexia risk management.

Development of the Preschool Developmental Assessment Scale (PDAS) on Children's Social Development.

This paper aimed to describe the design and development of the social domain of the Preschool Developmental Assessment Scale (PDAS), which would be used for assessment of preschool children with different developmental disabilities. The original version of the social domain consisted of 30 items. Children were asked questions about their social development such as their relationship with others, understanding of social norms and rules, empathy and perspective taking. The test was administered to 324 children, including 240 children from preschools and 84 children with developmental disabilities. Rasch analysis was conducted, and all except one item were within the acceptable range of infit statistics. The revised 29-item version could well differentiate between children with typical development and children with developmental disabilities. It could also differentiate between children from different age groups. The revised version was estimated to take around 15 min to administer. The social domain of the PDAS was found to be a direct, quick yet reliable assessment tool for assessing the social development of preschool children.

Development and validation of a new Chinese reading chart for children

This study aimed to develop and validate a new Chinese reading chart for children. The characteristics of reading profiles among Hong Kong children were also investigated.

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.