Bayley-III Special Needs Addition

When problems are suspected with the development of a child, developmental assessment is often carried out as part of the diagnostic process. A problem with existing instruments is that they are not suitable for children with special needs. This is caused by floor effects, the reliance of test results on language, motor skills and vision and the absence of information about developmental potential. This is striking, because children with special needs are particularly in need for developmental assessment.
In December 2009 a research project has started at the |Department of Special Needs Education with the aim of making the Bayley-III, a widely used instrument for the developmental assessment of young children, applicable to children with special needs. The test and its materials are adjusted for use with children with motor impairments and / or visual impairments (low motor / low vision version) and language or hearing problems (non-verbal version). Also, a dynamic assessment procedure was developed, aimed at giving information about the learning potential of a child. In the past few months a pilot study was carried out on the adjusted versions of the instrument. The results will be used to finalise the adjusted versions of the Bayley-III. In 2011 and 2012, the main research will be carried out, for which a sample of at leas 420 children with special needs will be tested with the adjusted versions and the standard version of the test. Test results on the standard version will be used to develop an adaptive test procedure based on item response theory. If found valid en reliable, the developed instrument will be published by Pearson Test Publishers in 2014.