The matching of groups is a traditional way to control for confounding variables in developmental disabilities research. The equivalency of means across groups is routinely checked for these variables, but not the homogeneity of their variances or the shapes of their distributions. In the present paper, it is argued that group matching can go…

Williams syndrome (WS), a neurodevelopmental genetic disorder due to a microdeletion in chromosome 7, is described as displaying an intriguing socio-cognitive phenotype. Deficits in prosody production and comprehension have been consistently reported in behavioral studies. It remains, however, to be clarified the neurobiological processes…

Matched samples of 174 pairs of persons with mental retardation who live in either community settings or congregate care settings were compared on both cost and outcome dimensions. It was learned that costs were significantly lower in community programs. Greater levels of service and integration were evident in the community programs, but…