The authors report on the development of a brief dyslexia screening measure based on revising the 65-item Hong Kong Behaviour Checklist of Specific Learning Difficulties in Reading and Writing. Teachers' ratings of 1063 primary students aged 614 years on the behaviour checklist provided data for its psychometric evaluation using traditional measurement and Rasch measurement model analyses. Rasch scaling suggested that the revised 36-item checklist could be regarded as a unidimensional scale that assesses global dyslexic dysfunction, and receiver operating characteristics analysis suggested that a score of 18 could be an optimal cut-off score when it is used as a dyslexia screening measure. The validity of this revised checklist was supported by its substantial and significant correlations with external measures of literacy and cognitive skills. Implications of the findings for the use of adaptive testing to provide an effective procedure for screening are discussed.
[Copyright of International Journal of Disability, Development and Education is the property of Routledge. Full article may be available at the publisher's website:
http://dx.doi.org/10.1080/1034912X.2012.676437 ]

Data of item responses to the Hong Kong Specific Learning Difficulties Behaviour Checklist from 673 Chinese primary grade students were analyzed using the dichotomous Rasch measurement model. Rasch scaling suggested that the data fit the model adequately with a latent dimension of global dyslexic dysfunctioning. Estimates of item attributes and person functioning on the same logit scale allowed the locations of person functioning to be interpreted in terms of item content. The substantial correlation between person estimates and external criterion measures (literacy and cognitive skills) provided support for the validity of the checklist in identifying children at risk for dyslexia. A common cutoff score based on person estimates across grades is suggested to replace the different cutoff scores based on conventional test scores for different grades. Implications of the findings for the use and the future development or refinement of the checklist are discussed.
[Copyright of Australian Journal of Learning Difficulties is the property of Routledge. Full article may be available at the publisher's website:
http://dx.doi.org/10.1080/19404150903524598]

Primary school teachers rated the frequency of occurrence of 65 reading-related behavioural characteristics in a sample of 251 Grade 1 to Grade 6 Chinese school children in Hong Kong. These behavioural characteristics were in the areas of general performance, reading, dictation, writing, mathematics, language, memory, concentration, sequential ability, motor co-ordination, spatial orientation, and social/emotional adjustment. Of these 12 areas, 10 yielded scale scores that could distinguish children with dyslexia from those without dyslexia, identified on the basis of their performance in five domains of literacy and cognitive skills. Using a summary score derived from the 10 relevant scales, an optimal cut-off score was suggested to arrive at a balance between high sensitivity and an acceptable rate of false positives in screening for children with dyslexia. The need for cross-replication in screening children with dyslexia using the behaviour checklist with different samples of school students is emphasised.
[Copyright of Educational Psychology is the property of Routledge. Full article may be available at the publisher's website:
http://dx.doi.org/10.1080/0144341042000271769]

Based on the data of the normative study of the Hong Kong test of specific learning difficulties in reading and writing, and the Test of visual-perceptual skills (non-motor) - Revised, 99 children aged between 6 and 10½ years were identified as children with dyslexia out of the normative sample of 690 children. By excluding 12 children known to score below average in IQ, 87 children, including 20 children not tested for IQ, could be regarded as children with dyslexia, yielding a prevalence rate of 12.6% and a boy:girl gender ratio of 1.6 to 1. The figures would become 9.7% and 2.0 to 1 if the 20 children were omitted from computation. However, gender imbalance could not be readily explained by gender differences in reading-related cognitive abilities, as there were only minor and subtle differences. Regression analyses to evaluate the relative contribution of different cognitive abilities to reading and writing suggested that orthographic knowledge and naming speed were most important among children with dyslexia. Implications of the findings and the need for early intervention are discussed.
[Copyright of Educational Studies is the property of Routledge. Full article may be available at the publisher's website:
http://dx.doi.org/10.1080/03055690601068535]

Based on the data of a school-referred sample of Cantonese-speaking Chinese children who met the Hong Kong criterion of dyslexia, the authors estimated for developmental dyslexia of Chinese children aged between 6 and 10 in Hong Kong an incidence rate of 0.66 percent and a gender ratio of 3.29 boys to 1 girl over a four-year period. They also explored the differences in estimates based on this Hong Kong criterion that emphasizes cognitive markers with more conventional discrepancy- based criteria. In view of the possible biases in self-selection and underreporting in the data of the school-referred sample, the authors compared the figures with those derived from the sample of the normative study of the Hong Kong Test of Specific Learning Difficulties in Reading and Writing, which yielded an estimate of 9.7 percent in prevalence rate and boy-girl gender ratio of 2 to 1 over a one- year period. The differences in estimates based on the two samples and implications of the findings are discussed in light of the limitations of the study.
[Copyright of Australian Journal of Learning Difficulties is the property of Routledge. Full article may be available at the publisher's website:
http://dx.doi.org/10.1080/19404150802093695]