Data management and descriptive statistic computation were conducted using SAS 9.1. Both the maltreatment variable and the conduct problems variable were positively skewed. Therefore, the data were analyzed assuming normal continuous liability distributions underlie the ordinal variables. This method retains the statistical advantages conferred by the normality assumptions for the underlying liability, retains an explicit mapping between the underlying liability and observed behavior, and correctly recovers the underlying correlations and parameter estimates (Stallings et al. 2001). Derks et al. (2004) also found that analyses of categorical data results in correct parameter estimates being recovered, although statistical power is decreased.
