Both instruments will be used concurrently in a sample of (a) Flemish children and adolescents between 6 and 18 years of age, with (b) intellectual disability or intellectual disability and associated conditions (specifically autism spectrum disorder, Down Syndrome or Cerebral Palsy), and (c) who are attending or receive support from educational or social services in Flanders. Because of a limited sample size, only preliminary analyses were conducted.  Future research should invest in recruiting a larger sample in order to conduct detailed convergent validity analysis.