Developmental assessment in cases of PIMD:The opinion of support staff and psychologists about the suitability of the GTI and Bayley-III

Introduction: Developmental assessment is important to be able to adjust the support that is offered to a person with PIMD to his/her possibilities and needs. The focus of this poster is the suitability of two developmental assessment instruments: the Bayley-III and the GTI (GedragsTaxatie-Instrument; Behaviour assessment instrument). Objective: The objective was to make an inventory of the opinion of support staff and psychologists working with adults with PIMD about the suitability of the two instruments. Method: The Low Motor/Low Vision version of the Bayley-III and the GTI have been administered to 24 adults with PIMD (age range: 29-57 years), who were referred by the psychologists from two different organisations in the Netherlands. The support staff and psychologists completed evaluation forms about the suitability of the instruments for the target group. Results: The results showed that, although there is overlap between the GTI and the Bayley-III in terms of test content, both instruments are useful in the developmental assessment of adults with PIMD. The respondents evaluated the GTI more positively. The reported advantage of the Bayley-III was the fact that the test result gives information about the developmental level in the form of age equivalents in different domains. To be able to obtain a valid test result with the Bayley-III, the psychologists proposed adjustments, like broadening the floor and ceiling rules and allowing the use of materials that are familiar to the person who is being assessed. Conclusion/Discussion: The conclusion is that both the GTI and the Bayley-III are useful in the developmental assessment of adults with PIMD and that more research is necessary into the correct application of the Bayley-III in the diagnostic process of both adults and children with PIMD

The Bayley-III accommodated for motor and/or visual impairment:“Low motor/vision version”.

Introduction: The aim of the newly developed Low Motor/Vision (LM/LVi) version of the Dutch Bayley-III is to increase the suitability of the instrument for testing children with a motor and/or visual impairment. Method: We tested 64 children with motor and/or visual impairment with the Low Motor/Vision version and the standard Bayley-III, in counterbalanced order. In addition, we tested a control group of 41 children without impairment with both versions of the instrument. Test administrators filled in an evaluation form about the suitability of LM/LVi-version for the specific child tested.Results: The results will be available at the time of the conference. We expect that children with motor and/or visual impairment will obtain higher scores on the Low motor/vision version of the Bayley-III than on the standard version, which would show that the children benefit from the accommodations. The control group is expected to obtain equal scores on both version of the instrument, which would support the idea that the item content and item difficulty have not changed compared to the standard version of the instrument. If not all children with impairment benefit from the accommodations, we will study the characteristics of the group of children that does benefit from the accommodations.Discussion: If the outcomes of the study show that the accommodations increase the validity of the Bayley-III when testing children with motor and/or visual impairment, this will have major implications for practice. Developmental psychologists will then be able to assess the development of children with a motor and/or visual impairment more validly then is currently possible and will consequently be able to provide more adequate support and advice