This chapter provides brief descriptions of the study population and abusive and neglectful families, and the effect of the population of the county units on the analysis. It analyses the relationships between environmental variables and rates of child maltreatment. The population at risk was composed of 18,942,579 persons younger than 18 years of age. They were predominantly white, 2,735,278 were black, and 1,190,302 were members of other racial minorities. Data from American Humane Association provide a profile of families in the 18 study states in which child maltreatment occurred in 1980. The average age of victims of child maltreatment was 7.51 years. Child maltreatment is enacted almost exclusively within the family unit. Discriminant analysis is a powerful technique for identifying differences between groups. Most of the basic assumptions necessary to discriminant analysis are also required for regression analysis. The states of New York and Missouri were used to demonstrate the nature of the effect of modestly populated units of analysis.