The Common Language tools have now been used to collect data on several thousand children across many states in the European Union and the United States.
The information collected is of variable quality. Some is orthodox research data based on sound instruments, applied to representative samples and drawing on several sources of information. Much of the data, however, has been gathered for planning purposes and relies on judgements of professionals looking at case notes, and all the biases that implies.
Information collected for planning purposes is seldom sufficient for research. Nonetheless, when standard research methods are applied to the assembled data, patterns emerge. When defined in terms of their needs, or the seriousness of their impairment, there are clearly similarities between some children. Some of the common language practice tools are based on the idea that while all children are unique in some way, all share common features with other children. Much of the analyses is predicated on identifying common groups of children in need, or in establishing the level of impairment that some share with others.
In research, this analysis of groups would be viewed as taxonomy. There are some established taxonomies used to describe the social and psychological needs of children, for example the International Classification of Diseases grouping of psychological disorders (and its American counter-part the Diagnostic and Statistical Manual of Mental Disorders). But no taxonomy exists to capture several aspects of child development, including physical health as well as psychological health and the quality of family relationships as well as behaviour.The search for such a taxonomical framework is well beyond the reach of the Common Language project with its current resources. But some of the Dartington researchers have looked at the patterns of need and impairment that exist in the data to detect whether they have any predictive qualities; to see if they could be used to improve interventions for children in need. In time, as the reliability and validity of the instruments becomes clearer, it is intended to look for funds to systematically examine the potential for a taxonomy for children in need, and to develop it as another common language tool.