Vulnerable Children: Findings from the National Longitudinal Study of Children and Youth (review)

This book is a detailed summary and analysis of the findings from the data collected in 1994 and 1995 from the first cohort of the National Longitudinal Study of Children in Youth (NLSCY). The NLSCY represents a major contribution to our understanding of the state of child development in Canada and the social and demographic factors that are associated with the developmental trajectories of Canadian children. The NLSCY's nationally representative sample includes over 22,000 children aged 0 to 11 years from over 13,000 households. Subsequent cycles of the NLSCY will track the development of these children from the initial sample and new children will be added to the data base as well. Conducted by the Applied Research Branch of Human Resources Development Canada in partnership with Statistics Canada, the NLSCY is a major investment towards a better understanding of Canadian children and families with the intent of providing accurate and meaningful information that can inform policy development and implementation in Canada today in future years.

The book's 20 chapters by Willms and his colleagues present a richly detailed interdisciplinary set of perspectives on both the conceptual underpinnings of the NLSCY as well as on the data themselves. Perhaps the most significant theoretical contribution of this work is the clear description of the concept of "social gradient" and how these gradients can be used to better understand child development outcomes. They cite research that points to higher levels of children's achievements on developmental outcome measures in societies in which the overall level of the social gradient, the slope of the social gradient (i.e., the gap between the highest and lowest SES levels) and the statistical strength (i.e., predictive power) of the gradient have been shown to be useful tools in understanding the interplay between individual growth and development and the social contexts in which the developing child lives. Their use of the gradient necessarily entails the use of multiple data sources and the creation composite variables that can begin to reflect the complexity of the multiple levels of child, family, neighbourhood, municipal, and provincial that must be considered in this kind of multi-methodological study.

The NLSCY's strength is not just in its conceptual, longitudinal or developmental features, but in its multi-methodological approach to data collection. The core of the study is based on a detailed interview with the adult who is considered to be the "person most knowledgeable (PMK)" about the target child that includes items about the child's motor, social and cognitive development, temperament, pro-social behaviour and behaviour problems that are drawn from a variety of different measures. The PMK is also asked questions about the neighbourhood in which the family lives. The two standardized outcome measures are the Peabody Picture Vocabulary Test (PPVT) given to the preschool children and an adaptation of the mathematics achievement section of the Canadian Test of Basic Skills for elementary school-aged children. The teachers and principals of the school-aged children are also given questionnaires to complete.

The major thrust of the data analyses is to identify both the direct and the mediating social and contextual factors that impact upon the children's levels of development as reflected by both parental ratings and the standardized outcome measures. Willms and his colleagues should also be commended for reporting their statistics in an accessible and informative manner that will be meaningful to researchers, government officials, and non-specialists in the area of child growth and development. This is done through clear language and numerous side-bars that explain the nature of the statistical techniques that are used in the book.

The book is usefully divided into five sections that focus on different aspects of the definition, measurement and interpretation of childhood vulnerability as assessed through the NLSCY. These sections explain the NLSCY and the concept of the gradient, provide working definitions of childhood vulnerability, report data on the prevalence of childhood vulnerability and...