Purpose: The aim of this study was to develop a child self-report questionnaire measuring bilingual experience and self-perceptions of Spanish and English proficiency and establish preliminary evidence of validity and reliability for the questionnaire. Method: Participants included 113 Spanish-English bilingual children with and without…

Background: Accurate measurement of adaptive behaviour is important in both clinical and research contexts. While several good clinical measures exist, as well as brief research measures for adults with intellectual disability, there is need for a brief and efficient measure for research with children and youth. We present preliminary psychometric…

Recent insight into the underlying molecular and cellular mechanisms of fragile X syndrome (FXS) has led to the proposal and development of new pharmaceutical treatment strategies, and the initiation of clinical trials aimed at correcting core symptoms of the developmental disorder. Consequently, there is an urgent and critical need for outcome…

The 18 items' Non-Communicating Adult Pain Checklist (NCAPC) has been developed from the 27 items Non-Communicating Children Pain Checklist to better capture pain behavior of adults with Intellectual and Developmental Disabilities (IDD). As part of the NCAPC's measurement properties, internal consistency, reliability and sensitivity to pain have…

Purpose: Accurate description of an individual's communication status is critical in both research and practice. Describing the communication status of individuals with severe intellectual and developmental disabilities is difficult because these individuals often communicate with presymbolic means that may not be readily recognized. Our goal was…

Background: Individuals with Angelman syndrome (AS) seem to have a strong preference for water-related items. Until present, preference assessment in AS has not been reported. Methods: An adapted Dutch version of the Choice Assessment Scale (CAS) was administered by parents and other caregivers to 105 individuals with AS. The CAS was adapted by…

To assess the psychometric characteristics of the Verbal Behavior Assessment Scale, the 15-item questionnaire was administered to pairs of caregivers of 115 individuals with developmental disabilities. Exploratory factor analysis involving 11 more participants revealed evidence concerning the distinction of three different communicative functions…